Abstract: Growth, development, reproduction and yield of silkworms depend on the availability and supply of preferred host plants having good agronomic and nutritional characteristics. Eri-silkworm, Samia cynthia recini B. is a multivoltine and polyphgous insect feeding on diversified host plants among which castor is a primary host plant. There is differential preference for the different varieties of castor by S.c. ricini. In the present study, eight different castor genotypes; namely Abaro, Acc 106584, Acc 203241, Acc 208624, Ar sel, Bako, GK sel and local were evaluated for their merits as feed and nutritional sources for white plain S.c. ricini at Melkassa Agricultural Research Center, Ethiopia. The treatments were arranged in a Completely Randomized Design (CRD) in three replications. Fifty worms were used in each replication. Significant difference was observed in rearing performance of eri-silkworms when fed to leaves of different castor genotypes. Among castor genotypes fed to eri-silkworm, Abaro fed worms showed medium to maximum records of matured larval weight (8.17 g), effective rate of rearing (74.68%), survival rate (76.08%), cocoon weight (3.34 g), pupal weight (2.86 g), shell weight (0.48 g), silk ratio (14.49%), fecundity (382.00), hatchability (88.17%) and shorter larval duration (584.17 h). In conclusion, genotype Abaro was superior to the other genotypes in improving the rearing performance of eri-silkworms and can be recommended for further research and development work in integrating silkworm activities for silk and oil seed productions.