Primers with higher G + C content showed better random amplified polymorphic DNA (RAPD) patterns among the cassava varieties. Clusters of Cs in the decamer primer sequence also seemed to influence banding patterns. RAPD patterns arising from 13 custom-made 10 and 12-base primers with varying lengths of successive Cs further revealed that strings of 4 to 6 Cs at the 5 and 3 end tended to provide stronger DNA amplification. Using a combination of RAPD patterns from several primers, it was possible to identify the eight cassava varieties used in this study. One custom-made primer also showed potential application as marker for cyanogenic potential in cassava.