BACKGROUND: Informatics tools may help support hypertension management. OBJECTIVE: To design, implement and evaluate a web-based system for patient anti-hypertensive medication self-titration. METHODS: Study stages included: six focus groups (50 patients) to identify barriers/facilitators to patient medication self-titration, software design informed by qualitative analysis of focus group responses and a six-month single-arm pilot study (20 patients) to assess implementation feasibility. RESULTS: Focus groups emphasised patient need to feel confident that their own primary care providers were directly involved and approved of the titration protocol. Physicians required 3.3 +/- 2.8 minutes/patient to create individualised six-step medication pathways for once-monthly blood pressure evaluations. Pilot participants (mean age of 51.5 +/- 11 years, 45% women, mean baseline blood pressure 139/84 +/- 12.2/7.5 mmHg) had five medication increases, two non-adherence self-reports, 52 months not requiring medication changes, 24 skipped months and 17 months with no evaluations due to technical issues. Four pilot patients dropped out before study completion. From baseline to study completion, blood pressure decreased among the 16 patients remaining in the study (8.0/4.7 mmHg, p = 0.03 for both systolic and diastolic pressures). CONCLUSIONS: Lessons learned included the benefit of qualitative patient analysis prior to system development and the feasibility of physicians designing individual treatment pathways. Any potential clinical benefits were offset by technical problems, the tendency for patients to skip their monthly self-evaluations and drop outs. To be more widely adopted such systems must effectively generalise to a wider range of patients and be integrated into clinical workflow.