A cross-sectional survey of 200 health professionals has highlighted factors regarded as crucial to the implementation effectiveness of health interventions in Māori communities. Four levels of importance for implementation effectiveness were determined by paired sample t-tests, with teamwork and community autonomy the most important. Experience with a previous health intervention in Māori communities was reported by 24% of participants. On multivariate regression analysis, the key overall factors associated with participants’ rating of implementation effectiveness were process (p<0.01) and community (p<0.05).