Clerodendrum viscosum is a traditionally used medicinal plant. The present study aimed to analyze a detailed cytotoxic effect of the nonpolar petroleum ether fraction (AQPEF) of leaf aqueous extract of C. viscosum Vent. (LAECV) in Allium cepa root tip cells. The LAECV was fractionated with petroleum ether and tested for A. cepa toxicity at early hours (2 and 4 h treatment) at concentrations 0, 0.050, 0.100, 0.150 and 0.200 mg mL-1. The highest aberrant cell percentage (10.45%) was scored from 0.150 mg mL-1 followed by0.100 mg mL-1 (8.75%) concentration at 4 h treated samples. The AQPEF treatment induced a significant (p<0.0001) increase in micronuclei frequency; 4.31, 5.08, 5.05 and 3.05% respectively at concentrations 0.50, 0.100, 0.150, and 0.200 mg mL-1. The highest polyploid frequency (20.14%) induced with 0.100 mg mL-1 of AQPEF at 16 h recovery. 0.150 mg mL-1 is the most effective concentration of AQPEF to decipher its activity similar to colchicine (0.150 mg mL-1). In summary, the present study indicates petroleum ether is suitable for extraction of the active phytochemicals of LAECV having cytotoxic effects on A. cepa root tip cells. The AQPEF has colchicine like micronuclei, polyploidy, and mitotic abnormality inducing potentials in A. cepa root apical meristem cells.