Methodology, based on starch and polyacrylamide gel electrophoresis, was developed for determining isozyme electrophoregrams (patterns) of 16 enzymes of cassava (Manihot esculentaGrantz) varieties as potential genotype markers. Extracts of five different tissues (root, stem, leaf, petiole and bud) were examined. In general, the nodal portions of the shoots gave isozyme patterns with the largest number of bands. Petiole extracts gave similar results but bud extracts gave poor patterns. The limited number of varieties that were examined could be distinguished by sequential classification on the basis of the isozyme patterns of acid phosphatase, esterase, glutamate oxaloacetase transaminase and phosphoglucoisomerase. © 1987 Martinus Nijhoff Publishers.