© 2021, Malaysian Society of Pathologists. All rights reserved.Introduction: This study aimed to determine the immunohistochemical expression of the ERG gene in prostatic adenocarcinoma and to evaluate the relationships between ERG expression and clinicopathological parameters. Design: Cross-sectional study. Setting: Pathology department of a tertiary hospital. Materials and Methods: The prostatectomy materials of 122 patients diagnosed with prostate adenocarcinoma between 2004 and 2017 in Zonguldak Bülent Ecevit University Faculty of Medicine, Department of Pathology were included in the study. Main Outcome Measures: Clinical data were obtained from patient files and macroscopic data were obtained from surgery and pathology reports. ERG expression, age, prostate-specific antigen levels, Gleason pattern and score, Gleason grade, and pathological stage were recorded. Results: The mean age of the patients was 62.66 ± 5.81 years and overall preoperative PSA was 10.40 ± 8.88 ng/ml. ERG was positive in 52.46% of the patients. PSA levels were similar in ERG positive and negative samples (p = 0.935). There was no significant relationship between Gleason score and ERG positivity (p = 0.197). ERG expression did not change with regard to age groups (p = 0.441) or tumour stage (p = 0.371). Conclusion: This study shows that the frequency of ERG positivity was high in our patients and that ERG positivity was not associated with clinical and pathological features, such as PSA levels, Gleason score, age and pathological stage.