Sport consumers are the most important component that ensure the continuum of the sport industry. So, it is crucial to understand the factors affecting the Sport Consumer Behaviour (SCB). In this research, we tried to examine the factors that influence the attendance of sport spectators in the national league of basketball and volleyball in Iran. The results showed that internal motivators included success and wining, team support, player support, coach support, sport level support, sports support, and community support; while external motivators were comprised of promotion, media advertisement, player behaviour, excitement, aesthetic, athlete physical skills, role model. Internal constraints were lack of knowledge, lack of success, lack of interest from others, and lack of companionship. The motivators were assigned to those factors that encouraged the attendees and the constraints were considered those that prevented the attendance of fans and consumers. The external constraints and other variables were shown to have insignificant and significant effects, respectively, on sport consumer behaviour. Constrains and motivators of sport consumer behaviour can help the sport marketers for better planning and achieving greater benefits and consumer satisfaction.