BACKGROUND: Although there is no strong evidence of benefit, chest physiotherapy (CP) seems to be commonly used in simple pneumonia. CP requires equipment and frequently involves the assistance of a respiratory therapist, engendering a significant medical workload and cost. AIM: To measure and compare the efficacy of two modalities of chest physiotherapy (CP) guideline implementation on the appropriateness of CP prescription among patients hospitalised for community-acquired pneumonia (CAP). PATIENTS AND METHODS: We measured the CP prescription rate and duration in all consecutive CAP inpatients admitted in a division of general internal medicine at an urban teaching community hospital during three consecutive one-year time periods: (1) before any guideline implementation; (2) after a passive implementation by medical grand rounds and guideline diffusion through mailing; (3) after adding a one-page reminder in the CAP patient's medical chart highlighting our recommendations. Death and recurrent hospitalisation rates within one year after hospitalisation were recorded to assess whether CP prescription reduction, if any, impaired patient outcomes. RESULTS: During the three successive phases, 127, 157, and 147 patients with similar characteristics were included. Among all CAP inpatients, the CP prescription rate decreased from 68% (86/127) to 51% (80/157), and to 48% (71/147), respectively (P for trend <0.01 for trend). A significant reduction in CP duration was observed after the active guideline implementation (12.0, 11.0, 7.0days, respectively) and persisted after adjustment for length of stay. Reductions in CP prescription rate and duration were also observed among CAP patients with COPD CP prescription rate: 97% (30/31), 67% (24/36), 75% (35/47), respectively (P<0.01 for trend). The mean cost of CP per patient was reduced by 56%, from $709 to $481, and to $309, respectively. Neither the in-hospital deaths, the one-year overall recurrent hospitalisation nor the one-year CAP-specific recurrent hospitalisation significantly differed between the three phases. CONCLUSION: Both passive and active implementation of guidelines appear to improve the appropriateness of CP prescription among inpatients with CAP without impairing their outcomes. Restricting CP use to patients who benefit from this treatment might be an opportunity to decrease CAP medical cost and workload.