SummaryCluster analysis was used to classify cowpea cultivars developed for resistance toM. testulalisin Nigeria based on data collected on four damage parameters. The cultivars were grouped into classes for each of two locations under two protection regimes. Differences were observed in the groupings for the two locations while one cultivar, MR×6–84F was found to have wide adaptability in the presence or absence ofM. testulalisinfestation. This is particularly useful for the selection of breeding materials in cultivar improvement for specific or general ecological zon