RESUMEN
The present study was conducted in selected schools in Greater Cairo including both high and low socioeconomic areas [Heliopolis and El- Waily, respectively] randomly chosen. One thousand students were recruited through multistage random sampling. A self-administrative questionnaire was used and included questions demonstrating the socioeconomic data of the studied students and questions about the smoking habit, risk factors for starting smoking as well as health beliefs concerning this habit. Urinary continence was estimated in a sub sample of the students as a confirmatory test. The questionnaire revealed a total prevalence of smoking of 8%, most of them were from El-Waily area. Urinary continine revealed a possibility of nine extra smokers in Heliopolis which would raise the prevalence from 1% to 19% in this area. Causes of starting smoking were found to be mainly freedom from family bonds. Increased number of siblings and more pocket money were detected as risk factors. The fathers and mothers education and occupation had no role in their sibs smoking yet having smokers in the family affected the incidence of smoking. Most students swallowed rather than blew their tobacco and the source of their first cigarette was mainly a friend