With the swelling of climatic and environmental hazards, Biodiesel is playing the most potential and significant role as the sustainable source of energy. As a substitute for diesel, biodiesel has been getting the attention of researchers/scientists of all over the world. The R & D have indicated sustainability of biodiesel production from non-edible oil sources such as Jatropha and algal oil. The objective of the present study was to optimize the process parameters for the transesterification of algal oil using CaO and 80% wt CaO.Al2O3 as catalysts. A low temperature transesterification process was selected. A biodiesel yield of 88.89% was achieved with methanol/oil volumetric ratio (3.2:10) using 80% wt. CaO.Al2O3 as catalyst (1.56% w/w) in 125 min time at 50 degrees C temperature using Response Surface Methodology. It was Observed that catalyst concentration, reaction time and methanol/oil volumetric ratio had a significant effect on yield. Also, this model involving heterogeneous catalyst can be used in the industry for efficient biodiesel production from algal oil, thereby saving time and cost of the process in optimizing the process parameters. (C) 2017 Elsevier Ltd. All rights reserved.