Aqueous and methanolic leaf extracts of two medicinal plants, Clerodendrum inerme (L.) Gaertn. and C. viscosum Vent. (Family: Lamiaceae) were evaluated on root tip mitotic cells of Allium cepa L. for assessment of cytotoxicity relevant to their potential applicability for therapeutic uses. Results revealed mitodepressive as well as cytotoxic effects in mitotic cells of Allium test system following treatments with the extracts; however, the manifestation of effects was differential in relation to extract types and concentrations. Aberration types encountered in dividing and resting cells of A. cepa highlight cytotoxic potentiality of the extracts. The present study is therefore significant for biomonitoring of the cytotoxic effects with studied leaf extracts.