In team sports, athletes' goals may focus on the task (enhancing performance, developing better skills, etc.) or on ego (being better than the others, achieving superiority, etc.). This study investigated the relationships between athletes' goal orientation and their tendency to cooperate with teammates and coaches. 158 professional men (M age = 24.1 yr., SD = 4.6) who played on various sport teams participated in this study. Goal orientation was measured with the Portuguese version of the Task and Ego Orientation in Sport Questionnaire, and cooperation was measured with the Questionário de Cooperação Desportiva. Cooperation was positively correlated with task orientation, and negatively correlated with ego orientation. Overall, the findings support that in sports, directing the players' focus on task may promote prosocial behavior.