Biodiesel is an alternative fuel, which is similar to conventional fuel or fossilized fuel. Biodiesel can be produced from straight vegetable oil, animal fats/oil, tallow and waste cooking oil. In this study, waste cooking oil (WCO) was used to produce biodiesel, which were collected from several hotels and restaurants of Tangail municipality area. This study was accomplished by trans-esterification process where methanol (CH3OH), potassium hydroxide (KOH) and WCO were used as raw materials to produce biodiesel. In this study, we got 347 ml of biodiesel from 400 ml of WCO having conversion rate 86.7%. Moreover, physical properties of produced biodiesel including density, viscosity, flash point, water content were measured in this study, which were like the American standard of testing material (ASTM) value of biodiesel.