To determine the efficacy of oral theophylline compared with placebo in people with stable chronic obstructive pulmonary disease (COPD). Systematic review of randomized-controlled trials comparing oral theophylline with placebo for a minimum of 7 days in people with stable COPD. Twenty randomized-controlled trials were included in this review. The following outcomes showed significant improvement with theophylline compared with placebo: FEV1 and FVC both improved with theophylline (weighted mean difference [WMD] 0.10 L; 95% confidence interval [95% CI] 0.04-0.16 and WMD 0.21 L; 95% CI 0.10-0.32, respectively). VO2 max also improved with theophylline (WMD 195.27mL/ min; 95% CI 112.71-277.83), as did PaO2 and PaCO2 (WMD 3.18 mmHg; 95% CI 1.23-5.13 and WMD -2.36mmHg; 95% CI -3.52 to -1.21, respectively). Patients preferred theophylline over placebo (relative risk 2.27; 95% CI 1.26-4.11). Theophylline increased the risk of nausea compared with placebo (RR 7.67; 95% CI 1.47-39.94). This review has shown that theophylline still has a role in the management of stable COPD, and is preferred by patients over placebo. However, the benefits of theophylline in stable COPD have to be weighed against the risk of adverse effects.