We previously showed that 40 % of clinically stable patients hospitalised for community-acquired pneumonia (CAP) are not switched to oral therapy in a timely fashion because of physicians' barriers. We aimed to decrease this proportion by implementing a novel protocol. In a multi-centre controlled before-and-after study, we evaluated the effect of an implementation strategy tailored to previously identified barriers to an early switch. In three Dutch hospitals, a protocol dictating a timely switch strategy was implemented using educational sessions, pocket reminders and active involvement of nursing staff. Primary outcomes were the proportion of patients switched timely and the duration of intravenous antibiotic therapy. Length of hospital stay (LOS), patient outcome, education effects 6 months after implementation and implementation costs were secondary outcomes. Statistical analysis was performed using mixed-effects models. Prior to implementation, 146 patients were included and, after implementation, 213 patients were included. The case mix was comparable. The implementation did not change the proportion of patients switched on time (66 %). The median duration of intravenous antibiotic administration decreased from 4 days [interquartile range (IQR) 2-5] to 3 days (IQR 2-4), a decrease of 21 % [95 % confidence interval (CI) 11 %; 30 %) in the multi-variable analysis. LOS and patient outcome were comparable before and after implementation. Forty-three percent (56/129) of physicians attended the educational sessions. After 6 months, 24 % (10/42) of the interviewed attendees remembered the protocol's main message. Cumulative implementation costs were <euro>5,798 (<euro>20/reduced intravenous treatment day). An implementation strategy tailored to previously identified barriers reduced the duration of intravenous antibiotic administration in hospitalised CAP patients by 1 day, at minimal cost.