The engineering and morphological properties of custard apple seeds were measured and also the effect of moisture content was studied. The average length, width, breadth, weight of whole fruit and weight of seed were found to be 84.00 mm, 74.25 mm, 65.15 mm, 238.68 g and 0.300 g, respectively. The per cent peel, carpellary pulp, gritty pulp and seeds were recorded to be 46.77, 35.36, 11.63 and 6.24, respectively. The respective size, sphericity, bulk density, true density, porosity and angle of repose of seed was found in the range of 8.828 mm to 8.091 mm, 0.648 to 0.625, 642.42 kg/m3 to 684.03 kg/m3, 898.22 kg/m3 to 1002.73 kg/m3, 28.46 % to 31.74 % and 29.470 to 25.840. The size and sphericity was decreased while bulk density, true density and porosity were increased with decrease in moisture content of the seed from 15.40 % to 10.25 % d.b. The angle of repose was found to be decreased from 29.47o to 25.84o with decrease in moisture content from 15.40 % to 10.25 % d.b.