Objectives:
The aim of the study was to examine the gender differences and predictors of leisure versus non-leisure time physical activities among Saudi adolescents aged 14–19 years.

Material and Methods:
The multistage stratified cluster random sampling technique was used. A sample of 1,388 males and 1,500 females enrolled in secondary schools in three major cities in Saudi Arabia was included. Anthropometric measurements were performed and Body Mass Index was calculated. Physical activity, sedentary behaviours and dietary habits were measured using a self-reported validated questionnaire.

Results:
The total time spent in leisure and non-leisure physical activity per week was 90 and 77 minutes, respectively. The males spent more time per week in leisure-time physical activities than females. Females in private schools spent more time during the week in leisure-time physical activities, compared to females in Stateschools. There was a significant difference between genders by obesity status interaction in leisure-time physical activity. Gender, and other factors, predicted total duration spent in leisure-time and non-leisure-time physical activity.

Conclusions:
The study showed that female adolescents are much less active than males, especially in leisure-time physical activities. Programmes to promote physical activity among adolescents are urgently needed, with consideration of gender differences.