The emergency medical service (EMS) in Saudi Arabia is managed by each hospital through the Saudi Red Crescent Society (SRCS). There are approximately 165 ambulance stations in the country, each with two ambulances. The SRCS collects data on EMS requests and ambulance arrival times at the accident scene. Each emergency incident has its own implications (accident, fire, injury, etc.) and must be dealt with individually. The aims of this study are to evaluate ambulance rescue time, which includes response time, in the city of Riyadh, the capital of Saudi Arabia; to analyze this time for road traffic accidents; and to compare the response time in Riyadh with corresponding times in other countries. A sample of 874 emergency calls was collected during 1999. Ambulance rescue time consists of three components: response time, time at the scene and travel time to the hospital. Data analysis showed that rescue time is, on average, 35.84 min (S.D. = 6.43 min). Within this time, the average response time is 10.23 min (S.D. = 5.66 min). Other service components (e.g. ambulance time at the accident scene and travel time to the hospital) are analyzed and detailed statistics are given. Ambulance speed to the accident averages approximately 55.05 km/h (S.D. = 27.42 km/h). One primary finding is that there is room for improvement in the rescue time in Riyadh, which would save more lives, through an increase in the efficiency of ambulance team performance. A test statistic is developed in this study to carry out a simple hypothesis testing for percentiles. This test statistic, which is generic and can be used for other applications, is used to compare EMS response time in Riyadh with that in other parts of the world.