Background: Physically active physicians are more apt to counsel patients about exercise. Purposes: The purpose of this study was to determine the effect of a physician fitness program on resident physician cardiovascular fitness, physical activity behavior/stage of change, and physical activity counseling behavior/attitudes. Methods: A prospective, intervention study with measurements at baseline (before intervention), 3 months (immediately after intervention), and 6 months (3 months after intervention) evaluated a multifaceted exercise program for 48 internal medicine residents. Resident physician cardiovascular fitness, energy expenditure, physical activity stage of change, knowledge, attitudes, and counseling behavior were measured. Results: Resident physician fitness significantly declined over time (baseline VO2-170 = 29.1 ml/kg/min, first follow-up VO2-170 = 27.3 ml/kg/min, and second follow-up VO2-170 = 26.2 ml/kg/min; p = .001). Although there was no change in overall energy expenditure, the number of resident physicians in the precontemplation or contemplation stage of change significantly declined with a corresponding increase in the number in a "higher" stage of change at first (p = .0034) and second follow-up (p = .024). There was a nonsignificant increase in self-reported patient counseling. Resident physician counseling confidence and perceived success significantly improved at first follow-up only (p = .01 and p = .03, respectively). Conclusion: Although resident physician fitness and energy expenditure did not improve after intervention, a significant improvement in resident physician physical activity stage of change and attitudes toward patient counseling was noted. Randomized controlled trials are needed to confirm whether these changes are attributable to the intervention. Copyright © 2005 by Lawrence Erlbaum Associates, Inc.