Classroom teachers’ responses to a 2-year professional development program are presented. Sixteen 4th- and 5th-grade teachers involved in Project SPARK completed structured interviews, questionnaires, and written evaluations of program sessions. Although in Year 1 more than half of the teachers expressed concerns about schedules and equipment management, results indicated that the program helped increase their self-confidence when teaching physical education. Participants believed that students benefitted from their enhanced knowledge and instructional behaviors. Program components most appreciated included: the input received and responsiveness of the design team; opportunities to collaborate, discuss concerns, and problem-solve with each other and the facilitators; and having on-site and large-group-session modeling. Results indicated that the teachers were less enthusiastic about a self-management curriculum due to its behavioral emphasis, yet supported the assertion that an ongoing, supportive professional development program can substantially improve classroom teachers’ physical education programs.