Background Road traffic injuries have dramatically increased in previous decade in Iran. According to the literature, rate of road traffic injuries among children & young adults is high. The first step for an accurate planning is situational analysis of knowledge, attitude and practice (KAP) in road traffic injuries.

Objective Determining the KAP of road traffic injuries among children (9-14 years)& young adults (15–30 years) in Tehran-Iran.

Material and methods A descriptive study was performed among 304 Tehrani children(9–14) and 327 young adults(15–30) years from primary schools to university students who were selected by a proportionate randomised population based sampling method, in 2008. Data was collected by a structured validated & reliable (r = 0.8) questionnaire, after a completed consent from the subjects.

Results Mean SD of age in children and young adults were 11.7, 1.6 and 20.74.3, respectively. Overall 50.7% were boys. Among girls (9–14 years), practice scores were higher than boys (p < 0.001), and among boys (15–30 years) attitude and practice scores were higher than girls (p < 0.02). Among high school students, attitude score was higher than primary schools' students (p < 0.043). Among scholarships, attitude and practice scores were higher than the others (p < 0.001). Knowledge & practice scores were higher in primary school pupil liaisons than middle school pupil liaisons (p < 0.003).

Conclusion These findings revealed the essential need for a comprehensive educational plan on traffic injuries, to enhance knowledge, change attitudes & improvement of practice.