Meti shell contains calcium carbonate which can be calcined into CaO and used as a heterogeneous catalyst in biodiesel synthesis. This study evaluated the ability of CaO catalyst from Meti shell with concentrations of 1, 2, 3, 4, and 5% for the synthesis of biodiesel from Moringa seed oil at various transesterification times (1, 2, 3, and 4 hours). The presence of CaO in the Meti shell was indicated by diffraction at 2θ angles of 32.47o , 37.74o , 54.22o , 64.65o , and 67.67oC. Utilizing CaO 3% and a transesterification reaction time of 3 hours resulted in an Rf value corresponding to the standard biodiesel Rf ranges, i.e. 0.69 and 0.66, respectively. The synthesized biodiesel has the highest methyl oleate content of 59.16% with characteristics that have met Indonesian National Standard (SNI 04-7182-2006), including water content of 0.004%, an acid number of 0.06 mg KOH/g, saponification number 273.6 mgKOH/g, iodine number 78.678 g iodine/100 g, the cloud point is 10oC, the pour point is 21oC, however, the cetane number is still below the minimum number of 51.