Background: Warfarin has been found to be associated with a number of complications especially bleeding. Patients’ knowledge on warfarin can improve anticoagulation control with decrease in adverse drug reaction and other associated complications1. Objectives: 1. To assess the existing knowledge about warfarin therapy among patients with cardiovascular disease. 2. To evaluate the effectiveness of video assisted teaching on knowledge about warfarin therapy among patients with cardiovascular disease. 3. To associate the knowledge scores with demographic variables. Material and methods: Total 60 patients suffering from cardiovascular disease undergoing warfarin therapy were included in this study. Pre experimental one group pre test post test research design were used for the present study. Non–probability purposive sampling techniques were used for the selection of samples. Results: There is a significant difference between pre test and post test knowledge scores on knowledge about warfarin therapy.