OBJECTIVE: Patients with hypertension are often non-compliant with their medication. A study was conducted in a usual clinical practice setting in patients with essential hypertension to improve medication compliance by modifying behavior. METHODS: The trial was designed as a randomized, multi-center, open-label, two-arm study in patients with essential hypertension. Four thousand eight hundred sixty four patients recruited from general practice settings were randomized to receive angiotensin-receptor blocker irbesartan with (intervention group) or without (non-intervention group) a behavioral modification program (Avapromise) which was based on a model of change, and followed up for 12 months. Randomization to Avapromise was done by site (recruiting physicians' office) such that all the patients within one site were randomized to the same treatment regimen to avoid contamination and to minimize investigator bias. Patients were sub-grouped based on their stage of change in the behavioral change continuum, and the intervention was tailored to address the needs of the particular sub-group. Primary efficacy measure was rate and time to discontinuation with irbesartan. RESULTS: At the end of the study the total number of patient discontinuations was 1240 (25% of 4864). Of these, 611 (25.4%, 95% CI 23.7-27.2) occurred in the intervention group and 629 (25.5%, 95% CI 23.8-27.3) occurred in the non-intervention group. This resulted in a difference of -0.1% (-2.6 - 2.3) between the two groups (p = 0.94). The time to discontinuation was not different between the groups (p = 0.87). The extrapolated rate of discontinuation estimated from the Kaplan-Meier curve was also not different between the groups (intervention: 23.1%, 95% CI- 21.3-24.8, non-intervention: 23.5%, 95%CI- 21.8-25.3). CONCLUSION: This behavioral modification intervention based on a model of change was not effective in increasing compliance rates in patients with essential hypertension in this setting.