Laboratory bioassays of three local isolates of entomopathogenic hypomycetes against the cabbage-heart caterpillar, Crocidolomia binotalis Zeller (Lepidoptera: Pyralidae) and field efficacy of several formulations of Paecilomyces fumosoroseus (Wise) Brown and Smith were evaluated. Dosage-mortality bioassays revealed that all the isolates were able to cause mortality to second instar larvae. Majority of the larvae became moribund within two days after treatment. Exposures to doses varying from 2 x 101 conidia mL1 to 2 x 107 conidia mL1 resulted in mean larval mortalities from 10.3 to 100%. At concentrations exceeding 2 x 106 conidia mL1 larval mortality was in excess of 80% and 100% mortality was observed at 2 x 107 conidia mL1 for all three fungal species. Significant relationships (P<0.05) were obtained between log dosage and probit mortality for all the isolates. The EC50 for P. fumosoroseus was estimated at 1.926 x 103 conidia mL1, and was significantly lower than that of Beauveria bassiana (Bals) Vuill at 5.038 x 103 conidia mL1. The EC50 for Metarhizium anisopliae var majus (Metsch) Sorokin was significantly the highest, at 2.0 x 104 conidia mL1. The best isolate was P.fumosoroseus which had LT50 almost half a day lower at a comparable dosage of 2 x107 conidia mL1, with a gradient of 4.656 as compared to 4.356 for B. bassiana and 4.193 for M. anisopliae var majus. In field treatments, plants were sprayed with suspensions containing 107 conidia mL1. Mean percent mortality for all the treatments were in excess of 70% and significantly higher (P<0.05) than the control. Conidia in palm oil Vesawif® gave the most promising result against the cabbage-heart caterpillar.