Todd Schneider
President and Chief Executive Officer at Cintas
Thank you Paul. Our fourth quarter financial results are led by a strong revenue increase of 13.0% to $2.07 billion. Despite strong inflationary headwinds, operating income margin increased 10 basis points to 19.5% and EPS grew 13.8% to $2.81. Our sales force continues to add new customers and penetrate and cross-sell our existing base. Businesses prioritize, all we[phonetic] provide including image, safety, cleanliness, and compliance.
Challenge was finding labor to run their business, heighten concerns over sanitization and the inflationary labor and purchasing costs, businesses increasingly outsourced to Cintas to help them get ready for the workday. We were able to deliver increased operating margin and EPS despite this period of significant inflation by productively selling new business, penetrating existing customers with more products and services, providing excellent service while driving operational efficiencies, and obtaining incremental price increases from our customer base. Fourth quarter free cash flow increased 15.2% from last year.
On June 15, we paid shareholders $98.2 million in quarterly dividends and during the fourth quarter and through July 13, 2022, we purchased $496.5 million of Cintas common stock under our buyback program. We continue to allocate capital in many ways to improve shareholder returns. We are pleased with our fourth quarter financial results. They conclude a fiscal year of significant accomplishments, including the following. Fiscal year 2022 revenue was a record $7.85 billion, an increase of 10.4%. The organic revenue growth rate was 10.2%.
Excluding two gains recorded this fiscal year and one recorded last fiscal year, operating income margin increased 50 basis points to 19.7%. We allocated capital to improve shareholder return. Acquisition spend was $164.2 million. In fiscal 2022 and up until today, we repurchased 4.3 million shares of Cintas stock for a total of $1.62 billion. Also, we increased the dividend 26.7%. We have increased the dividend every year since going public, which is 38 consecutive years.
We made significant progress on our digital transformation journey. Our customers continue to find added value in managing their program through our online solution. We expect the ease of doing business with us to drive greater customer retention and faster revenue realization. We are actively using our new rolled out proprietary routing technology, which we call Smart Truck. This technology helps us make smarter routing decisions, enabling us to spend more time with our customers on service and sales, and also allows us to reduce energy usage and expense by driving fewer miles. We also made great strides in data analytics and enhanced business reporting, helping us target penetration, cross-selling, operational efficiencies, and pricing opportunities.
In addition, as part of our steadfast commitment to corporate responsibility, we issued our second environmental social and governance or ESG report. It's a more robust report. Cintas was founded on a sustainable business model. Our corporate culture is based on doing what's right and challenging ourselves to improve. With this in mind, we announced our ambition to achieve net zero greenhouse gas emissions by 2050. And finally, our actions are being recognized. We were again named to the prestigious Fortune 500. It's an honor to be recognized among the most successful and respected companies.
We were also recently added to the FTSE4Good Index Series. The Index Series includes companies demonstrating strong ESG practices. I thank our employees, whom we call partners, for their continued focus on our customers, our shareholders, and each other. Cintas has grown revenue and adjusted EPS in 51 of the past 53 years. And our prospects for continued profitable growth are great. They result in part from a strong value proposition and a vast total addressable market. Every business, goods producing or services providing, has a need for image, safety, cleanliness, or compliance.
Operating a business is increasingly complex. Rather than doing it themselves, businesses increasingly outsource to Cintas. We provide the products and perform the services better, faster, and economically frame businesses to concentrate on their core competency. Since every business has a need for image, safety, cleanliness, or compliance, our total addressable market is vast. The prospects for Uniform or workwear rental are significant. The unserved workwear rental market is tremendous. Tens of billions of dollars of workwear are sold by retailers each year to workers in every sector of the economy. There are millions of people in healthcare alone; hospitals, urgent care, doctors office, dentists offices, and long-term care going to work every day in shrubs purchased from retailers.
We focus on targeting these retail customers converting them to a rental program. The fact that consistently 60% of our new customers are converted from retail to a rental program speaks to the size of the opportunity, as well as our continued success. Plus, we are more than just a Uniform Rental company. More than half of our revenue is from facility services including hygiene, floor care items such as dust mats and mops, cleaning tools like microfiber mops and towels, first aid cabinet services, and fire protection services including test and inspection of extinguishers and alarms.
Every business that has a door, floor, wall, bathroom, and employees is a sales prospect. Our organic revenue growth rates are indicative of our compelling value proposition and tremendous market size. We grow revenue in multiples of GDP and jobs growth because of ample supply and demand for our products and services. Our growth in revenue is profitable growth and our operating margins have a long runway for expansion. Growth results in more buying power with our suppliers. It produces operating leverage.
Route density increases reducing energy expenses and providing more time to spend with customers on service and sales. Growth means more volume in the plants, covering fixed cost of building, machinery and equipment. And when we penetrate existing customers with more products and services, the incremental operating margins are even stronger because we realize more revenue [indecipherable]. The future of Cintas remains bright. I'll now turn the call over to Mike to provide the details of our fourth quarter results and our financial expectations for fiscal 2023.