Clerodendrum inerme is a widely used medicinal plant in tropical and subtropical regions of the world. The present study aimed to analyze the micronuclei (MN) and polyploid (PP) cell-inducing potentials of the leaf aqueous extract of C. inerme (LAECI) in Allium cepa root tip cells and compared with colchicine induced MN and PP in A. cepa root tip cells. The LAECI induced increased frequency of MN and PP in root tip cells at 4 h treatment followed by 32 h water recovery and the effects were found to be comparatively higher than the colchicine effects. Thus, LAECI may contain bioactive phytoconstituents having MN and PP inducing effects on A. cepa root tip cells, suggesting its colchicine-like application in karyotyping and plant breeding programs.