Background Many trials have compared anticoagulation management provided by a pharmacist led anticoagulation clinic versus usual physician care showing the role for clinical pharmacist in the management of anticoagulant therapy, and demonstrating excellent outcomes. In Sudan, there is no published research evaluating the role of pharmacist in providing pharmaceutical care for patients taking warfarin. Objective The objective of the study is to assess the role of clinical pharmacist intervention in warfarin patients compared to usual medical care. Setting This study was conducted in Ahmed Gasim cardiac surgery and renal transplant center warfarin clinic. Methods One hundred thirty-five patients were randomly selected from adult patients on warfarin therapy The history of INR records, and adverse effects for the past year, were recorded. Then patients' warfarin dose adjustments according to INR, was done by the clinical pharmacist for one year. Patients received continuous verbal education and written information about warfarin. Main outcome measure The primary outcome for this study was the INR control, while the secondary outcomes were the bleeding events and hospitalization due to warfarin. Results After the clinical pharmacist intervention there was significant (P < 0.01) improvement in INR control and a significant (P < 0.05) reduction in incidence of bleeding after clinical pharmacist intervention. Hospitalization due to warfarin related complications (bleeding, high INR, low INR) was also significantly (P < 0.001) reduced. Conclusion Clinical pharmacists intervention in warfarin therapy improve INR control, reduce bleeding and hospitalization due to warfarin complications.