This study examines the use of a cooperative physical games program "The Game Factory" on social behaviour among children. Children are required to work together towards positive collective outcomes. A pretest-intervention-posttest design is used. Parents and teachers assessed 90 Australian primary school children in two experimental groups and one control group. Experimental groups undertook 6 fortnightly program sessions. Results suggest that the program results in significantly improved pro-social behaviour in the school environment and general improvements in pro-social behaviour in the home environment. Findings support the use of cooperative games to increase pro-social behaviour among children. (Contains 1 table and 2 figures.)