Aim The aim of this study was to investigate the impact of a pharmacist-led pharmaceutical care programme, involving optimization of drug treatment and intensive education and self-monitoring of patients with heart failure (HF) within the United Arab Emirates (UAE), on a range of clinical and humanistic outcome measures. Methods The study was a randomized, controlled, longitudinal, prospective clinical trial at Al-Ain Hospital, Al-Ain, UAE. Patients were recruited from the general medical wards and from cardiology and medical outpatient clinics. HF patients who fulfilled the entrance criteria, and had no exclusion criteria present, were identified for inclusion in the study. After recruitment, patients were randomly assigned to one of two groups: intervention group or control group. Intervention patients received a structured pharmaceutical care service while control patients received traditional services. Patient follow-up took place when patients attended scheduled outpatient clinics (every 3 months). A total of 104 patients in each group completed the trial (12 months). The patients were generally suffering from mild to moderate HF (NYHA Class 1, 29.5%; Class 2, 50.5%; Class 3, 16%; and Class 4, 4%). Results Over the study period, intervention patients showed significant (P < 0.05) improvements in a range of summary outcome measures [AUC (95% confidence limits)] including exercise tolerance [2-min walk test: 1607.2 (1474.9, 1739.5) m·month in intervention patients vs. 1403.3 (1256.5, 1549.8) in control patients], forced vital capacity [31.6 (30.8, 32.4) l·month in the intervention patients vs. 27.8 (26.8, 28.9) in control patients], health-related quality of life, as measured by the Minnesota living with heart failure questionnaire [463.5 (433.2, 493.9) unit·month in intervention patients vs. 637.5 (597.2, 677.7) in control patients; a lower score in this measure indicates better health-related quality of life]. The number of individual patients who reported adherence to prescribed medications was higher (P < 0.05) in the intervention group (85 vs. 35), as was adherence to lifestyle advice (75 vs. 29) at the final assessment (12 months). There was a tendency to have a higher incidence of casualty department visits by intervention patients, but a lower rate of hospitalization. Conclusions The research provides clear evidence that the delivery of pharmaceutical care to patients with HF can lead to significant clinical and humanistic benefits. Keywords: Heart Failure, clinical pharmacy, pharmaceutical care, health outcomes, RCT