This study addresses the implementation effects of an in-service training program on self-regulated learning for secondary school teachers. A quasi-experimental, treatment-control group investigation was designed to test the effects of this program. Study results suggested that the in-service program on self-regulated learning had little or no effect on the application of regulation strategies by secondary school teachers in the lower grades of the comprehensive school. No significant differences between trained and untrained teachers were found for the Observation Scale for Self-Regulated Learning and the Student Scale for Self-Regulated Learning. Possible interpretations of this outcome are: (1) the training of the teachers may be too short in duration; (2) the generally passive character of student learning in secondary schools; (3) the workshops were conducted after school; and (4) the training on self-regulated learning was isolated from a more comprehensive training program involving a Dutch adaptation of the program "Dimensions of Learning" from the Association for Supervision and Curriculum Development (ASCD). (Contains 27 references.) (Author)