RESUMO
<p><b>OBJECTIVE</b>To analyze the time factor in road traffic accidents (RTAs) in Fars Province of Iran.</p><p><b>METHODS</b>This study was conducted in Fars Province, Iran from November 22, 2009 to November 21, 2011. Victims'information consisted of age, sex, death toll involving dri- vers or passengers of cars, motorcycles and pedestrians, and site of injury etc. Accidents were analyzed in relation to hour of the day, season of the year, lighting condition including sunrise, sunset, daytime and nighttime.</p><p><b>RESULTS</b>A total of 3 642 deaths (78.3% were males, and the ratio of males to females was about 3.6:1) were studied regarding their autopsy records. There was a steady increase in fatal accidents occurring at midnight to 15:59. The risk of being involved in a fatal traffic accident was higher for those injured between 4:00 to 7:59 than at other times (OR equal to 2.13, 95% CI 1.85-2.44). The greatest number of fatal RTAs took place in summer. Mortalities due to RTA during spring and summer were more pronounced at 20:00 to 23:59 and midnight to 3:59, whereas mortalities in fall and winter were more pronounced from 12:00 to 15:59.</p><p><b>CONCLUSION</b>The high mortality rate of RTA is a major public health problem in Fars Province. Our results indicate that the time is an important factor which contributes to road traffic deaths.</p>