Objective: A Competitive Oral Health Game was applied as an educational strategy for prevention in the schoolchildren community.  This game was designed  through participatory action research and is intended to compare  the oral knowledge, attitude and practice (KAP) in terms of the traditional existing program in Guadalajara, Mexico.  Methods: An action design research was used in which the educational intervention is the basic tool to achieve a positive change of behavior in preventive oral health in the school community. The active participation of children, parents, and teachers was essential in developing and redesigning the competitive oral health game. The game was designed in accordance with the age (12 years old) and condition of the children  within the school community. An experimental and a control group were chosen (2 schools with similar sociodemographic characteristics),  pre- and post-measurements were performed by trained examiners using intra- and inter-calibration (.96 and .96 Kappa). Results: The educational strategy constructed with the participation (self-reflection and workshops) of schoolchildren , teachers and parents was the COHG. A significant statistical difference (p<.05) was found between the participatory and the traditional programs for schoolchildren among the independent variable (COHG) and the dependent variable (KAP). Conclusions: The COHG, as an educational participatory prevention strategy for oral health care for schoolchildren, focuses in health promotion with more effectiveness than the traditional program of oral health. This game is going to be used as a model with follow up evaluation research during the next four years in Jalisco Mexico, and then the program will be established in 5,888 schools in this state for 12 year-old children.