We report the application of a method which combines digestion with pancreatin and neutral detergent treatment in the analytical study of dietary fiber from cassava. The use of pancreatin previous to the detergent extraction enabled rapid filtration, thus giving more reproducible results for neutral detergent fiber (NDF). Acid detergent fiber (ADF), hemicellulose, lignin and pectin were also determined. The values obtained for NDF (4.65%) and pectin (1.17%) are very important, considering their role in the digestive process.