Namibian ethno-medicinal plants have not yet been evaluated for their efficacy in inhibiting the activities of Human Immunodeficiency Virus (HIV) reverse transcriptase (RT) and their toxicological effects to mammalian cells have not yet been reported. Hence the aims of this study were: (1) to evaluate selected Namibian plants for their biological activities against RT; (2) to evaluate their toxicity to mammalian cells, and (3) to isolate and characterize the active compounds from selected plant extracts. Colorimetric assays were used to evaluate RT inhibition and cell viability.