Baculoviruses (Family Baculoviridae) have been used to control Lepidopteran pests in China, Japan and India. Several studies on baculoviruses have been done in Kenya but there has been no commercial use. Collection of local isolates and characterization is recommended to identify and select the most potent isolate for use in mass production. Two Kenyan isolates of Plutella xylostella granulovirus, from field-collected and insectary larvae respectively, were characterized by electron microscopy and bioassays. The isolates were found to show the typical morphological features of Baculovirus in the genus granulovirus. The results of surface contamination bioassays for both isolates exhibited the characteristic dose-mortality response curve, with LD50 values that were not significantly different from each other. The median survival time of 2nd instar larvae at an average temperature of 25°C ranged from 5.5 to 7.5 days depending on the virus concentration to which the larvae were exposed. Further investigation is recommended.