Lime as a cheap and abundant constructional material has shown good activity for catalyzing biodiesel production from waste frying oil. In the present work, due to lack of data for optimum operating conditions and interaction effects, an optimization study was performed using response surface methodology. The effects of catalyst weight percent, MeOH/Oil molar ratio and calcination temperature in relation to oil conversion as response were also investigated and optimized. Using Box-Behnken design and quadratic polynomial model, the optimum level for catalyst weight percent, MeOH/Oil molar ratio and calcinations temperature were determined as 3 wt%, 13.1, and 716.2 °C, respectively. At these conditions, the anticipated oil conversion was 92.3%. Catalyst weight percent and calcination temperature are two parameters that mainly affect the oil conversion and a significant interaction can be observed between them.