The objetive of this work was to determine the physiological maturity and the harvest time of andropogon seeds. The experiment was conducted at Goiânia during 1981 to 1985. The experimental design used was a randomized complete block with four replications and seven treatments (harvest time): 20, 26, 32, 38, 44, 50 and 56 days after initial head emergence (lHE). The seeds were harvested by hand and dryed under shade, from april until may. The parameters analysed were: seed prodution, germination, yield of pure germinating seed, pure germinating seed, first counting, weigh of thousand seeds, moisture content, dry matter of seeds and head density. The analysis of the data obtained led to the following conclusions: a) the head emergence is concentrated; b) the best harvest time occurs from 30 to 38 days after IHE; e) the physiological maturity of seeds is attained between 32 and 38 days after IHE.