Aim: The study aimed to evaluate antimicrobial and cytotoxicity of Grewia villosa, Cassia abbreviata and Hoslundia opposita. Methods: Microdilution method and brine shrimp lethality test were employed to evaluate antimicrobial and cytotoxicity of plant extracts. Results: The extracts of G. villosa, C. abbreviata and H. opposita showed different levels of antimicrobial activities on Gram negative bacterial and fungal species tested. The minimum inhibition concentration (MIC) ranges of G. villosa, C. abbreviata and H. opposita extracts were 0.391-25, 0.195-25 and 0.391-25 mg/mL respectively. Cassia abbreviata stem methanolic extracts and roots ethyl acetate extracts exhibited the highest activity with minimum inhibition concentration (MIC) of 0.195 mg/mL against S. typhi and K. oxytoca respectively. At least one of the extract from each plant exhibited a cytotoxicity nature when tested on brine shrimps where the G. villosa stem chloroform extract was the most cytotoxic with fifty percent lethal concentration (LC50) of 48.432 μg/mL. Conclusion: The findings in this study validate the traditional use of G. villosa, C. abbreviata and H. opposita in management of bacterial and fungal infections. Further phytochemical investigations on G. villosa, C. abbreviata and H. opposita growing in Pare Mountains are recommended to contribute to drug development.