Nine cassava (Manihot esculenta) genotypes were grown for three years (1992-1993, 1993-1994 and 1994-1995) in three agro-ecological zones in Nigeria to study their reaction to cassava anthracnose disease (CAD), caused by Colletotrichum gloeosporioides, investigate genotype x environment (G x E) interaction patterns for their reaction to anthracnose, and to identify genotypes with stability of resistance to the disease. Mean squares for environments, genotypes and G x E interactions were highly significant (P