Background: H2-receptor antagonists and proton pump inhibitors account for approximately 15% of primary care prescribing costs in the UK. Aim: To examine the use of antisecretory drugs in primary care between October 1991 and September 1996. Methods: Analysis of prescribing data from an ongoing postal survey performed every 3 months on a rolling quota of 250 UK general practitioners (GPs), identified from a representative sampling frame of 1000 GPs, Results: There were 8,811 new courses of proton pump inhibitors and 11,945 new courses of H2-receptor antagonists during this study. The number of new prescriptions for proton pump inhibitors increased by 174.5%, but decreased for H2-receptor antagonists by 12.5%. Proton pump inhibitors were mostly prescribed for reflux disease (52.7%) and H2-receptor antagonists for non-specific dyspepsia (43.6%). Proton pump inhibitors (14.1%) were less likely to be stopped than H2-receptor antagonists (35.3%) overall, and they were less likely to be stopped because of perceived ineffectiveness (5.3%) than H2-receptor antagonists (23.8%). The rate of stopping treatment because of side-effects was about 3% for both classes of drug. Conclusions: Prescribing of proton pump inhibitors has increased sharply each year since 1991. One reason may be that GPs receive proton pump inhibitors to be more effective than H2-receptor antagonists.