Waste cooking oil (WCO) is one of the main sources which creates water pollution and in that way harmful for the environment. It is readily available in different fast-food centers, food processing industries, cafeterias and local restaurants. The proper reuse of WCO helps the society in many ways like additional income to restaurants and fast-food outlets, prevents blockage of drains due to presence of unwanted materials, minimizes water contamination due to toxic materials in WCO and preserves aquatic lives. So for cleaner environment, it can be reutilized as biodiesel after processing, as cooking fuel and also in construction of asphalt pavement. So studies need to be done on the characterization of WCO samples for the determination of quality and suitability of end products. In the present research investigation, twenty samples of WCO were collected from different sources and ten important characteristics like free fatty acids, peroxide value, kinematic viscosity, density, moisture, saponification value etc. have been analysed. Based on results, it is possible to predict the ultimate use of the samples properly.