This study explores the role of Prostate Specific Antigen (PSA) as a tumour marker in prostate cancer diagnosis and prognosis.A cohort of 120 participants aged 45 to 70 years underwent a cross-sectional analysis of PSA levels and their correlation with tumour characteristics.Data collection involved structured interviews and medical record reviews. Diagnostic assessments, including histopathological analysis and Gleason scores (6 to 9), were performed. PSA levels were correlated with tumour characteristics. Statistical analysis utilized IBM SPSS Statistics.The distribution of PSA levels (mean: 8.52 ng/mL, median: 7.89 ng/mL) reflected variations. A positive correlation (0.67) existed between PSA levels and Gleason scores. Receiver Operating Characteristic analysis yielded an AUC of 0.82, indicating good diagnostic accuracy.The study provides insights into PSA's diagnostic potential and its correlation with tumour characteristics in prostate cancer.Acknowledging limitations, this research prompts validation efforts to bridge research and clinical understanding.