The constructs of cognitive-developmental psychology are applied in this study to the practice of teacher education with the objective of creating a developmental learning environment designed to stimulate personal/professional growth and cognitive structural change on the part of the teacher. The 37 inservice elementary and secondary school teachers and other support personnel involved in the study participated in a summer workshop and fall practicum that were geared toward teacher psychological development in the stages of ego, moral, and conceptual growth. Pretest and posttest measurements were administered, and analysis indicated that the inservice program did facilitate growth in ethical reasoning and conceptual complexity. The inservice experience did not appear however to impact the most general level of ego development. Results suggested as well that it is more difficult to create effective developmental experiences for adults than for children. (DS)