Participation is the core of reform to the health sector; its implementation depends on many factors as the attitudes of individuals involved. The author’s objective was to analyze attitudes and opinions on participation of Colombian users, health care personnel and policy makers. An exploratory and descriptive research was carried out, in 25 focal groups of 210 users, 40 leaders, and 36 individual semi-structured interviews to health care personnel, combining qualitative and quantitative methods with a survey to 1497 users. It was found that most of the actors have a positive attitude towards participation, which was more favorable among women, people with basic studies and low socioeconomic level, retirees and the unemployed. It was also found that health care personnel had ambivalent attitudes favorable opinions towards participation, but unfavorable ones about the situational elements that determine it.