Background: Anticoagulants are commonly indicated for the treatment and prevention of thromboembolism. Their complications are very serious concerns and can cause death and health care wastages. Unfortunately, there is no adequate information known on the magnitude and correlates of anticoagulant related complications in Ethiopia. The aim of this study was to assess the prevalence of complications and associated factors related to anticoagulant therapy among patients who were admitted at University of Gondar Comprehensive Specialized Hospital.

Methods: Institution based, retrospective study was conducted from July 1 to August 30 on hospitalized patients who were admitted at University of Gondar Comprehensive Specialized Hospital from January to June, 2017. Data was collected from medical charts of patients using structured checklist. Different descriptive statistical methods and logistic regression analysis to assess factors associated with anticoagulant related complications were carried out.

Results: One hundred fifty four patients’ medical charts with anticoagulant indication were reviewed. The most common indication of anticoagulants was deep vein thrombosis 114(74.0%) from which 35 (30.7%) were provoked deep vein thrombosis cases. Among patients who have been treated with anticoagulants 51 (33.1%) showed complication. Patients’ age >65 (AOR=4.703(1.24–17.76)), sex (AOR=4.62(1.38-15.53), treatment modification (AOR= (6.46(1.65-25.27) were significantly associated with complication related to anticoagulant therapy.

Conclusions: Complications related to anticoagulant therapy were prevalent. This study underlined the seriousness of the problem and need of inter-collaborated work of all health care decision makers.

Key words: Bleeding, Anticoagulant therapy, Complications, Warfarin, Heparin