The impact of size and diversity on group process and outputs. This study has analyzed the impact of size and diversity on group processes (group cohesion, effective management of conflicts, and group norms) and outputs (work satisfaction and group effectiveness) in a sample (N= 407) of Mexican workers. It considered two types of diversity: functional and social diversity. Hierarchical regression analysis revealed main effects for size and functional diversity. Size is negatively associated with group norms, effective management of conflicts and job satisfaction. Functional diversity is positively related to group norms and cohesion. However, social diversity was not related to group process and outcomes. The analysis revealed a moderating effect of functional diversity on the relationship between size and job satisfaction. The practical implications of these results are analyzed.