The Motivation Toward the Environment Scale (MTES), developed in Canada, measures people’s self-determined motivation for doing something for the environment. Answering the call by its original developers, this study further validated the MTES within a sample of 779 Dutch-speaking senior secondary school students, aged 17 to 19, in the north of Belgium. More specifically, reliability and construct validity of a Dutch translation of the MTES were verified. To this measure, confirmatory factor analysis was used, and the hypothesized simplex structure was tested through correlation analyses. Results confirmed the reliability of the MTES and a five-scale version of the MTES, excluding identified motivation, is introduced. This variable-centered approach was complemented by the adoption of a person-centered approach for identifying MTES profiles. Using cluster analysis, four meaningful MTES profiles emerged, with amotivation scoring medium to high in all but one. Theoretical implications of the findings and suggestions for interventions and further research are discussed.