Abstract: Previous research lags behind in illuminating theoretical mechanisms that shape governance decision-making on board practices. Using an integrated theoretical approach, I examine how board interlock network and institutional factors are associated with board governance policy adoption in nonprofit organizations. A linear regression model is employed to investigate policies adopted by a panel of public charities in three cities in Upstate New York during 2008 and 2014. Results show that not only the presence of board interlock networks but also central network positions relate to extensive policy adoption. Results also reveal that the use of paid professionals in management relates to institutional isomorphism reflected by more extensive governance policy adoption. These results provide insights for nonprofit leaders seeking to facilitate good governance practices by paying attention to board members’ affiliations and institutional environment considerations.