J. Michael Hansen
Executive Vice President and Chief Financial Officer at Cintas
Thanks, Todd, and good morning. Our fiscal '24 fourth quarter revenue was $2.47 billion compared to $2.28 billion last year. The organic revenue growth rate adjusted for acquisitions and foreign currency exchange rate fluctuations was 7.5%.
Gross margin for the fourth quarter of fiscal '24 was $1.22 billion compared to $1.09 billion last year, an increase of 11.6%. Gross margin as a percent of revenue was 49.2% for the fourth quarter of fiscal '24 compared to 47.7% last year, an increase of 150 basis points.
Strong growth from new customers and the penetration of existing customers with more products and services helped generate great operating leverage, aided by the performance of our global supply chain and focused efforts to extract inefficiencies from the business via our Six Sigma and engineering teams as well as technologies like SmartTruck.
The Uniform Rental and Facility Services operating segment revenue for the fourth quarter of fiscal '24 was $1.91 billion compared to $1.77 billion last year. The organic revenue growth rate was 7.1%. As we have done in the past, I will share revenue mix of the Uniform Rental and Facility Services operating segment for the fourth quarter. Keep in mind, there can be small fluctuations in mix between quarters.
Uniform Rental was 48%, dust was 19%, hygiene was 16%, shop towels were 4%, linen, which includes microfiber, wipes, towels, and aprons was 10% and catalog revenue was 3%. These percentages are consistent with last year and demonstrate we are experiencing strong demand across all our products and services.
Gross margin for the Uniform Rental and Facility Services operating segment was 48.6% compared to 47.7% last year. This 90 basis point improvement was the result of good top line growth that continued to generate great operating leverage and excellent sourcing and process improvements, which continued to create additional efficiencies such as garment sharing and SmartTruck.
Our First Aid and Safety Services operating segment revenue for the fourth quarter was $277.6 million compared to $249.8 million last year. The organic revenue growth rate was 11.1%, capping off another year of double-digit organic growth. Gross margin for the First Aid and Safety Services operating segment was 55.4% compared to 51% last year. This 440 basis point improvement was the result of our double-digit revenue growth that created solid operating leverage and improved sales mix, a dedicated First Aid distribution center that has lowered costs as well as efficiencies from our SmartTruck technology.
Our Fire Protection Services and Uniform Direct Sale businesses are reported in the all other segments. All other revenue was $282.1 million compared to $261.5 million last year. The Fire Protection revenue was $197.9 million and the organic revenue growth rate was 12.9%, resulting in another year of double-digit organic growth. The Uniform Direct Sale revenue was $84.2 million and organic revenue decreased 4.4%. The organic growth rate in Uniform Direct Sales can vary from quarter-to-quarter.
Gross margin for Fire Protection Services was an all-time high at 50%, compared to 47.9% last year. This 210 basis point improvement was primarily the result of robust revenue growth that generated strong operating leverage along with route productivity improvements. Gross margin for Uniform Direct Sales was 40.9% compared to 36% last year. This 490 basis point improvement was the result of higher margin accounts from a disciplined approach to the market.
Fourth quarter selling and administrative expenses as a percent of revenue was 27%, which was a 10 basis point improvement from last year. We were able to create leverage with these costs while continuing to invest in technology and selling resources. Fourth quarter operating income was $547.6 million compared to $470.8 million last year.
Operating income as a percentage of revenue was 22.2% in the fourth quarter of fiscal '24 compared to 20.6% in last year's fourth quarter. The fourth quarter marks the first time that all three operating segments, Uniform Rental and Facility Services, First Aid and Safety Services, and Fire Protection Services exceeded 22% in operating income in the same quarter.
Our effective tax rate for the fourth quarter was 21.4% compared to 22.4% last year. Net income for the fourth quarter was $414.3 million compared to $346.2 million last year. This year's fourth quarter diluted EPS was $3.99 compared to $3.33 last year, an increase of 19.8%.
I'll now turn the call back over to Todd to provide his thoughts on next year and our financial expectations for fiscal '25.