Abstract: The fitness and productivity of silkworms is largely influenced by the varieties of mulberry leaves they feed on. The overall aim of this research was to contribute to the development of the silk value chain through assessing the best variety for optimum growth and productivity of silkworms in Uganda. Hatching to the first spinning ranged from 21 to 24 days while feeding was done 2-3 times a day. Bombyx L. silkworms were fed with leaves of three mulberry varieties (Morus alba. L) i.e; Thailand, Local and Thika harvested from the research experimental gardens of Namasumbi village, Kyampisi Sub-county in Mukono district. Parameters like larval length, weight, survival rate, cocoon weight, pupae weight, shell weight and shell ratio were recorded on 10 randomly selected worms. Thailand variety was observed significantly superior in length (P=0.0001), weight (P=0.0001), survival worm (P=0.000), cocoon yield in grams (P=0.045), cocoon (n) yield (P=0.0038) shell weight (P=0.036), rate of cocooning (p<0.05). Percentage shell ratio also scored higher in Thailand (21.1%). No significant difference in pupa weight (P=0.06) , Total pupa yield (0.089) and filament length (P=0.5374).Thailand was significantly associated with early molting, spinning, and cocooning, converse to Thika and Local. The overall performance of B. mori in terms of fitness and productivity was significantly improved with Thailand variety. Therefore, it has the potential to enhance the commercial qualities of silk and hence recommended for higher yield of silk.