Adenocarcinoma of the prostate has been known as a disease of the aging males. It is commonly diagnosed in the industrialized countries and becoming an increasing burden in the developing countries because of increasing health awareness and life expectancy. Diagnosis is made by digital rectal examination (DRE) of the prostate for malignant features beside an elevated prostate specific antigen (PSA) and positive prostate biopsy results on histology. Gleason score derived by adding the two (2) predominant histologic patterns helps in prognostication of individual patient. In this study, we retrospectively studied the relationship (correlation) between serum PSA and Gleason Score (GS) in Prostate Cancer (PCa) Patients. One hundred and ten (110) patients diagnosed with Pca between January 2016 and December 2017 were studied. Their case notes from the health records department were retrieved and data collected together with their histopathology reports of prostate biopsy from the pathology records department. Pre-biopsy PSA were correlated with Gleason score. Results showed that majority of the men presented with a serum PSA >50ng/ml with a corresponding high Gleason Score (Gs of 9). PSA also correlated positively with Gleason Score. Therefore patients with high PSA may likely harbor tumours with high Gleason scores indicating poor prognosis.