An evaluative study was done of Project THISTLE (Thinking Skills in Teaching and Learning), a program designed to improve the basic skills of urban college-bound high school students by working with their teachers in an integrated process of curriculum and staff development. In particular, the evaluation looked at the impact of the program on teachers, as perceived by the teachers themselves and by their supervisors. Of the several Newark (New Jersey) high schools participating in Project THISTLE, faculty members from one school, Malcolm X Shabazz High School (MXSHS), were evaluated. At the MXSHS, 29 faculty members were graduates of the program. Data were collected through interviews with 10 of the faculty members and questionnaires administered to 9 supervisors. The data suggest that teacher participation in Project THISTLE resulted in positive teaching changes, especially with a thinking skills focus, and in greater involvement in curriculum development. Teachers shared their significant satisfaction in having the opportunity to participate in the Project. Teachers also spoke about the excitement in collegial participation in the Project and how this feeling was subsequently diminished. Included are copies of correspondence, forms, and instruments used in the study in three appendixes. (JB)