In this research work, the optimization of enzymatic starch hydrolysis of cassava for ethanol production was investigated. Two hundred milliliter (200ml) samples of 50g/l cassava starch solutions were hydrolysed using α and β amylase (isolated enzymes), pure culture of the amylolytic fungus Aspergillus niger (whole cells) and a combination of α and β amylase and Aspergillus niger. Subsequently, the hydrolysed starch was fermented using Saccharomyces cerevisiae and the ethanol produced collected after distillation of 100 ml of each sample. Ethanol production from the samples was in the order α and β amylase/Aspergillus niger> Aspergillus niger> α and β amylase >> unhydrolysed starch. Increase in ethanol production for the hydrolysed starch was due to conversion of starch to simple sugars by the activities of the enzymes thereby providing more simple sugars for direct fermentation to ethanol by the yeast. There was no significant difference in ethanol production using isolated enzymes  and whole cells individually in hydrolysis, but there was significant difference using combination of isolated enzymes and whole cells p<0.05. It took 1 hour for hydrolysis using isolated enzymes and took 72 hours using whole cells. The results showed that the amount of ethanol produced depended on the degree to which the starch was hydrolysed and that isolated enzymes were more efficient than enzymes synthesized from whole cells for starch hydrolysis. Cassava is a good producer of ethanol considering its potentially high yields. The cassava starch used in this work yielded approximately 1.96 liters of ethanol per kg of starch at the highest yield. Asides from its high yield of ethanol, cassava has an outstanding ecological adaptation, accounting for its being widely cultivated around Nigeria and West Africa and can be successfully grown in poor soils with low labour requirement, low capital and ease of cultivation.