Several intersectoral community approaches targeting childhood obesity (IACOs) have been launched in the Netherlands. Translation of these approaches into practice is however arduous and implementation. We therefore studied the implementation of five IACOs in the Netherlands for one-and-a-half years. IACO implementation was evaluated via an adapted version of the MIDI questionnaire, consisting of 18 theory-based constructs. A response rate of 62% was obtained. A hierarchical multivariate linear regression model was used to analyse our data; the final regression model predicted 65% of the variance in adherence. Higher levels of self-efficacy, being an implementer embedded in community B, and having more than 1 year of experience with IACO implementation were associated with higher degrees of adherence. Formal ratification of implementation by management and being prescribed a higher number of activities were related to lower degrees of adherence. We advise that, when designing implementation strategies, emphasis should be placed on the enhancement of professionals' self-efficacy, limitation of the number of activities prescribed and allocation of sufficient time to get acquainted and experienced with IACO implementation. Longitudinal studies are needed to further evaluate interaction between and change within critical determinants while progressing through the innovation process.