Yam peel was used as a carbon source to produce extracellular amylase in shake flask cultures of a thermophilic strain of Aspergillus Aspergillus niger. Peak amylase activity was obtained on the 4th day of the 6-day fermentation period which corresponded with the early stationary phase of the organism. The mycelial dry weight was not significantly affected by either yam peel or soluble starch but a higher rate of amylase activity was obtained when the organism was grown on yam peel than when soluble starch was used as the sole carbon source. The optimum temperature and pH of the enzyme was 70 degrees C and 5.5, respectively, with more than 50% enzyme activity retained al 80 degrees C (30 min).