Do physicians apply an early-switch strategy (from intravenous to oral antibiotics) in clinically stable patients hospitalised with community-acquired pneumonia (CAP)? If not, why not? In a multicentre prospective cohort study, adult patients admitted for i.v. CAP treatment were included. On day 3 of antibiotic treatment, clinical stability was assessed and treating resident physicians were interviewed on their switch strategies. Additionally, treating physicians were interviewed to evaluate their knowledge of and adherence to guideline advice. 149 (92%) out of 162 patients were included and 97 (91%) out of 107 physicians were interviewed. A switch to oral antibiotics was possible in 68 (46%) out of 149 patients on day 3 of treatment but not performed in 27 (40%) out of 68. Patient factors delaying the switch were high CURB-65 (confusion of new onset, urea >7 mmol · L(-1), respiratory rate of ≥ 30 breaths · min(-1), blood pressure <90 mmHg or diastolic blood pressure ≤ 60 mmHg, and age ≥ 65 yrs) score (on admission) (p=0.04) and oxygen treatment (p=0.04), high temperature (p=0.00) and high respiration rate (p=0.04) (day 3). Physicians' barriers to an early switch in clinically stable patients included misconceptions (26 (55%) out of 47), practical considerations (13 (28%) out of 47) and organisational factors (eight (17%) out of 47). Strikingly, 91 (94%) out of 97 interviewed physicians were not aware of guideline advice. The switch from i.v. to oral antibiotics is often unnecessarily delayed in patients hospitalised with CAP due to different types of barriers.