The performance of every plant in an environment is an indicator of how the plant can withstand the various environmental conditions. This study investigated the toxicity of crude oil on the growth performance, chlorophyll contents, enzymatic activities and oxidative stress biomarkers of eight accessions of Zea mays. The growth enzyme (amylase and invertase) activities, as well as oxidative stress biomarkers (malondialdehyde, peroxidase, superoxide dismutase and catalase) in Z. mays were assayed using spectrophotometric method. The maize accessions were grown in the experimental pots containing crude oil treatments (2%, 4%, 6%, 8% and 10%) and harvested after 14 days of seedling emergence. The results showed that the percentage seedling emergence, leaf area, root length, stem girth and shoot length of each accession were significantly reduced (p