Nineteen Rhizopus strains were selected and tested for their growth capacity on raw cassava starch and their ability to produce amylase when grown on solid-state fermentations. Only three strains grew significantly on this natural substrate. Glucoamylase production was higher on raw cassava than on cooked cassava. After 48 h of fermentation, the protein content of cassava was increased from 1.75% to 11.3%. The byproducts of fermentation were fumaric acid, lactic acid and ethanol.