Background: Guideline and reimbursement modifications have been introduced to optimize prescribing of antisecretory medication in Danish general practice. Impacts of the interventions have not been evaluated. Objectives: To analyse developments in prescribing of antisecretory medication in Denmark 2001-2011 and to assess the impacts of interventions on prescribing of antisecretory medication. Methods: Register-based cohort study covering the entire Danish population of currently 5.5 million inhabitants. Developments in the prescribing of antisecretory medication over time in Denmark between 2001 and 2011 and association with age and gender of users along with the impact of interventions on the prescribing of drug subgroups are analysed. Results: 96.8% of all antisecretory drugs sold are proton pump inhibitors (PPIs) and 94.4% of the PPIs are prescribed in primary care. Prescribing of PPIs has increased substantially during the past decade. Both number of users and the average individual use have increased. The prescribing of ulcerogenic drugs to the elderly has stagnated in the same time range. Reimbursement modifications and scientific guidelines do not seem to have had a substantial influence on the steadily increasing prescribing of PPIs. Conclusion: Use of PPIs has increased substantially during the past decade, without a change in indications for use of PPIs in the same time range. Interventions to enhance adherence to guidelines and promote rational use of PPIs do not seem to have had a substantial influence on the overall prescribing rate.