This study investigates the impact of demographic diversity variables (age, gender, and functional background) and social structure variables (i.e. tie strength) on entrepreneurial team effectiveness. Using information collected through a questionnaire, administrated to 202 entrepreneurs representing 51 entrepreneurial teams, this study shows that functional and demographic diversity is not significant for entrepreneurial team effectiveness, whereas the network constraints based on strong ties do have a significant effect on team effectiveness. Thus, being conscious of the different factors associated with team effectiveness encourage the accompanists to provide assistance, which facilitates the team building process.