J. Michael Hansen
Executive Vice President & Chief Financial Officer at Cintas
Thanks Todd and good morning. Our fiscal 2024 third quarter revenue was $2.41 billion compared to $2.19 billion last year. The organic revenue growth rate adjusted for acquisitions, foreign currency exchange rate fluctuations and a difference in the number of work days was 7.7%. Total growth was positively impacted by 170 basis points due to the extra workday. We remind you as you update your models for next fiscal year that there will be two less work days compared to this current fiscal year.
Each quarter next year will have 65 work days, which means the first and the fourth quarters will each have one less workday than this fiscal year. Organic growth by business was 7.1% for Uniform Rental and Facility Services, 11.5% for First Aid and Safety Services, 13.9% for Fire Protection Services, and Uniform Direct Sale was down 3.9%. Gross margin for the third quarter of fiscal '24 was $1.19 billion compared to $1.03 billion last year, an increase of 14.9%. Gross margin as a percent of revenue was 49.4% for the third quarter of fiscal '24 compared to 47.2% last year, an increase of 220 basis points.
Strong volume growth, technology improvements, and continued operational efficiencies helped generate this strong gross margin. Gross margin percentage by business was 48.8% for Uniform Rental and Facility Services, 56.3% for First Aid and Safety Services, 48.8% for Fire Protection Services, and 41.1% for Uniform Direct Sale. Gross margin for the Uniform Rental and Facility Services segment increased 170 basis points from last year. Energy was a tailwind of 40 basis points. In addition, we continue to leverage our strong revenue growth, our technology investments and extract inefficiencies out of the business through our Six Sigma and engineering teams.
Our technology investments have allowed us to improve garment sharing among our plants, which improves material cost. Our SmartTruck technology allows us to improve our route efficiencies and provide route densities to our existing routes, which positively impacts truck purchasing, labor and energy. Our Six Sigma and engineering teams have helped us create efficiencies in the plant that allow us to maximize the utilization of our plant equipment, labor and energy. Gross margin for the First Aid and Safety Services segment increased 470 basis points from last year.
Strong revenue growth continues to help expand our margins in this segment. Strong revenue performance in some of our high margin recurring revenue products like AED rentals, Eyewash Stations, and WaterBreak continues to provide a healthy revenue mix. Our technology investment in SmartTruck continues to provide route optimization and improved efficiencies, and our First Aid dedicated distribution center allows us to lower product costs. All of these contribute to improved gross margins. Selling and administrative expenses increased 90 basis points from last year.
The increase was driven by investments in selling resources, technology and our management trainee program, as well as costs associated with an agreement in principle to settle the purported class action contract dispute brought by plaintiff, City of Laurel. We determined that settling the claim is in the best interest of Cintas. The total monetary payment agreed to in the proposed settlement, including the 60 basis points recognized in this quarter is $45 million. We expect that the settlement costs will not impact our financials in future periods.
As Todd mentioned earlier, we generated strong cash flow. For the year our free cash flow increased 31.6%. This has allowed us to invest back into the business, which has resulted in capital expenditures of 4.3% for the year. Our investments include technology to grow the top line and expand margins, automation to improve efficiencies in our plants and additional processing capacity where needed. We expect capital expenditures to finish around 4.25% of revenue for the year. Operating income of $520.8 million compared to $446.8 million last year.
Operating income as a percentage of revenue was 21.6% in the third quarter of fiscal '24 compared to 20.4% in last year's third quarter, an increase of 120 basis points. Our effective tax rate for the third quarter was 19.9% compared to 22.1% last year. The tax rates in both quarters were impacted by certain discrete items, primarily the tax accounting impact for stock based compensation. Net income for the third quarter was $397.6 million compared to $325.8 million last year.
This year's third quarter diluted EPS of $3.84 compared to $3.14 last year, an increase of 22.3%. Todd provided our annual financial guidance. Related to the guidance, please note the following: fiscal '24 interest expense is expected to be $99 million compared to $109.5 million in fiscal '23, predominantly as a result of less variable rate debt. Our fiscal '24 effective tax rate is expected to be 20.6%. This compares to a rate of 20.4% in fiscal '23.
Our guidance does not include the impact of any future share buybacks. As I mentioned earlier, we expect that the proposed settlement will not impact our financials in future periods and accordingly there's no impact on our guidance. Guidance includes $17.4 million of acquired revenue for the fourth quarter. This revenue includes the impact of the recently announced acquisitions during the third quarter.