The effectiveness of an alliance may be influenced by a number of factors including managerial and power imbalances, conflict, organisational compatibility, prior history and the length of the relationship. While the relationships between these variables have been examined in the literature, no study to date has examined whether the perceived effectiveness of the alliance differs depending on whether the collaboration has a strategic or tactical emphasis. This study examines relationships in the context of alliances from environmental non-profit organisationsa?? perspectives. The findings indicate that there are differences in the factors influencing perceived alliance effectiveness and governance for tactical and strategic alliances. The implications of the findings are discussed and future research directions are identified.