The laboratory experiments were carriedout at the Institute of Organic Farming (IOF), UAS, Dharwad, during 2014-2015 to study the bioefficacy of different formulations of Metarhizium anisopliae against coconut rhinoceros grubs, Oryctus rhinoceros (Linnaeus). Among different oil based formulation, rice bran oil (60%) + corn oil (40%) formulation found least LC50 value (1.99 x 10 6 cfu/ml) at 432 h. In granular and wettable powder formulation, the granular formulation recorded least LC50 value 0.44 x 10 8 cfu/g at 240 h. The medean lethal time (LT50) of different oil based formulations, the rice bran oil (60%) + corn oil (40%) formulation @ 3 x 10 6 cfu / ml recorded lower LT50 value of 319.89 h (13.32 days). Among granular and wettable powder formulation, the granular formulation @ 5 x 10 8 cfu / g, proved most effective exhibiting 50 per cent of mortality with least LT50 value of 162.88 h (6.78 days).