Abstract: Fusarium pallidoroseum isolated locally from cadaver of Lymantria obfuscata was evaluated as bio-control agent against caterpillars of same pest at concentrations of 1x1010, 1x109, 1x108, 1x107, 1x106, 1x105, 1x104, 1x103, 1x102 and 1x101 spores mL-1. No mortality was observed up to 3rd day of inoculation. 1x1010 spores mL-1 was the most promising concentration as it inflicted an initial mortality of 43% on the 4th day and cent percent mortality on the 9th day. The LC50 values ranged from 1.969x103 (16th day) to 1.256x1011 (4th day). A linear positive association was observed between mortality and days of observation.