Pleural infection is increasing in incidence. Despite optimal medical management, up to 30% of patients will die or require surgery. Case reports suggest that irrigation of the pleural space with saline may be beneficial. A randomised controlled pilot study in which saline pleural irrigation (three times per day for 3 days) plus best-practice management was compared with best-practice management alone was performed in patients with pleural infection requiring chest-tube drainage. The primary outcome was percentage change in computed tomography pleural fluid volume from day 0 to day 3. Secondary outcomes included surgical referral rate, hospital stay and adverse events. 35 patients were randomised. Patients receiving saline irrigation had a significantly greater reduction in pleural collection volume on computed tomography compared to those receiving standard care (median (interquartile range) 32.3% (19.6-43.7) reduction versus 15.3% (-5.5-28) reduction) (p<0.04). Significantly fewer patients in the irrigation group were referred for surgery (OR 7.1, 95% CI 1.23-41.0; p=0.03). There was no difference in length of hospital stay, fall in C-reactive protein, white cell count or procalcitonin or adverse events between the treatment groups, and no serious complications were documented. Saline irrigation improves pleural fluid drainage and reduces referrals for surgery in pleural infection. A large multicentre randomised controlled trial is now warranted to evaluate its effects further.