Abstract: Experiments were conducted in 2005, 2006 and 2007 at the Teaching and Research farm of the University of Agriculture, Makurdi, Nigeria, to study the effects of variable harvest ages (days after anthesis-DAA) on the quality of ‘egusi-itoo’ melon (Cucumeropsis mannii Naudin.) seed. A bulk crop was raised and fruits that developed from date-tagged flowers were harvested at five days interval beginning from 20 DAA to 65 DAA in 2005 and from 15 DAA to 60 DAA in 2006 and 2007 to monitor seed development and maturation with time. End of the seed-filling phase was attained at 50 DAA in 2005 and 40 DAA in 2006 and 2007. The highest seed germination values of 96.5, 93.5 and 94% were obtained in 2005, 2006 and 2007 respectively at the last harvest (60/65 DAA). Germinability of stored seeds increased with DAA and the longevity of more mature seeds was better than that of less mature seeds. It was therefore concluded that delayed harvest until when fruits were between 60 and 65 DAA resulted in higher quality seeds of Cucumeropsis mannii.