Renewable fuels have received more attention in the last few decades since the fuel demand is constantly increasing. In this scenario, fuels from vegetable oils are emerging as an interesting alternative. In this study, biodiesel produced from used cooking oil was studied. Several concentrations of biofuel were tested to evaluate their performance and combustion characteristics i.e. 7% (B07), 17% (B17), 27% (B27), 52% (B52), 77% (B77) and 100% by volume of Biodiesel (B100) on conventional diesel. Tests were conducted in a single cylinder four-stroke compression ignition engine. A 1-D computational model was built and compared to experimental results. The biodiesel concentration in the blends had influence on engine performance by increasing fuel consumption due to its reduced lower heating value. In addition, larger fractions of biodiesel on conventional diesel presented higher peak of heat release. Based on these preliminary results, it was found that biodiesel from cooking oil has the potential to partially or totally replace conventional diesel in compression ignition engines.