Amylase production by Humicola and Paecilomyces species was investigated in different media; starch yeast-extract medium was the most suitable for both fungi. streptomycin favoured enzyme production by Humicola sp. in this medium at concentrations of up to 75 mug/ml, whereas with Paecilomyces sp. amylase production was adversely affected at above 50 mug/ml streptomycin. The optimum temperatures for amylase production by Humicola and Paecilomyces species were 45 and 35-degrees-C with 8 and 6 days incubation, respectively, and the Humicola enzyme was thermally stable up to 50-degrees-C. The amylase synthesis in both fungi appeared to be inducible by starch.