Purpose: This study examined the feasibility and acceptability of implementing research-tested physical activity (PA) behavior change counseling (BCC) sessions in an existing cancer-exercise program, and the preliminary effects on cancer survivor’s self-efficacy and PA. Methods: Participants were cancer survivors undergoing or within six-months of completing cancer treatment(s), and exercise program staff. Cancer survivors were randomized to receive the exercise program plus PABCC, or the standard exercise program. Feasibility and acceptability were assessed by recruitment, adherence, satisfaction, and a focus group with program staff. Qualitative data were analyzed using descriptive thematic analysis. Self-report questionnaires measured PA and exercise self-efficacy. Results: Recruitment was 33 out of 93 (36.7%), and n = 13 (39%) provided post-program data. Cancer survivors enjoyed PABCC sessions, but reported face-to-face delivery was an added time burden. Program staff expressed desire to implement PABCC, but perceived staff capacity and time as barriers to sustainability. Exercise self-efficacy increased by 21.5% in the PABCC group vs. 4.2% in the control. PA increased by 81.3% in the PABCC group vs. 16.6% in the control group. Conclusions: Implementing PABCC in an existing cancer-exercise program was acceptable and promising for increasing moderate to vigorous PA, but additional research is needed to enhance the feasibility and sustainability of translating efficacious behavioral interventions into existing cancer-exercise programs.