Investigations were carried out to determine the composition of fungal flora in the studied sites. Samples of the raw effluent were collected along the flow channel and the retention pond. Water samples were also collected at the discharge point and up and down stream of the river from the discharge point. The samples were spinned at a speed of 250rpm for 10minutes and spread inoculated the deposits on potato carrot agar (PCA) and potato agar supplemented with 7.5% Nacl. Inoculated plates were incubated aerobically at room temperature in dark cupboard for 7days. Fungal colonies that emerged on the primary culture plates were distinguished into types. The pure isolates were characterized into genera using standard taxonomic guides. Genera such as Aspergillus, Penicillium, Curvularia, Fusarium, Microsporum, Trichoderma, Rhizoctonia, Nigrospora and Chaetophoma species were detected in the raw effluent. However, Microsporum, Trichoderma, Rhizoctonia, Nigrospora and Chaetophoma species were conspicuously absent in the effluent retention pond. Only Trichoderma and Chaetophoma species were absent in water samples collected at the treated effluent discharge point into the recipient River. Samples of water collected up stream of the discharge point did not contain Geotrichum, Nigrospora and Chaetophoma species. Curvularia, Microsporum, Rhizoctonia and Nigrospora species were not detected in water samples collected downstream of the discharge point. It was therefore concluded that, fungi constitute a significant proportion of the microflora of sites contaminated with the refinery effluent and could be playing an important role in the remediation of sites receiving the effluent. © JASEM Keywords : Fungal flora, Refinery effluent, Retention ponds, Discharge point, Upstream, Downstream