The rising global demand for palm oil and its associated products has led to increased numbers of palm oil refineries with its attendant effluent discharge. Many researches have confirmed the ecological disruptive potentiality of Palm Oil Mill Effluent (POME), still further attention has to be directed at POME’s potential genotoxicity. The present study has made physico-chemical and genotoxicity assessments of POME from a corporate refinery in Nigeria, using the American Public Health Association (APHA) procedures along with Allium cepa root assay. Allium cepa roots were grown in graduated concentrations of POME and the roots were analyzed for chromosomal aberrations. Results suggest that POME caused growth inhibitions and chromosomal aberrations in A. cepa roots. with mitotic index of A. cepa roots dropping as POME concentrations were increased. The chromosomal aberrations induced in A. cepa were vagrant, sticky chromosomes, bi-nucleated cells, and C-mitosis. These results indicate that palm oil mill effluent is not only capable of causing ecological disruptions in the receiving environment, but is also potentially genotoxic to resident organisms. It is recommended that if effluents from palm oil mill refineries cannot be converted to other useful products and ought to be disposed of, it should first be properly treated and tested for genotoxicity.