The purpose of this study was to compare factors affecting casual, regular and enthusiastic spectators’ attendance at football pro-league matches. Descriptive research method was applied in this study. Iran pro-league clubs were divided to three groups according to their continuous attendance at pro league matches. Sample included 490 spectators determined by Cochran formula and proportionally distributed to three groups. A researcher-made questionnaire was used according to Correia and Esteves’ (2007) model for data collection. Questionnaire reliability was confirmed by factor analysis, related masters and professionals, and validity by Cronbach alpha (? = 0.870). Questionnaires were distributed among four stadiums (Tehran, Hamadan, Isfahan and Qazvin). Data was analyzed by factors analyses , K-S, Friedman, Kruskal Wallis and Mann-Whitney U tests. Data analyses results showed that economic factors (ticket price, transportation expense) and stadium facilities were the most important factors that affected all three group spectators’ attendance. Team relatedness (favorite players, good team performance, evaluation of coaches and players performance, player’s loyalty to the team and taste victory) and aggreesiveness (insult referee, on pitch aggressiveness, humiliate opposite team) had significant differences in attendance of casuals, regular and enthusiatsic spectators.