Diploma thesis title: Relationship between PSA level and pathohistological findings in transurethral resection of the prostate Objectives: The main goal of this study was to see whether PSA can indicate inflammation in the pathohistological finding in patients operated on at the Department of Urology of the Clinical Hospital Center Split during the period from 2019 to 2021. Subjects and methods: We conducted a retrospective clinical study comparing the relationship between the clinical status of patients before planned transurethral resection, PSA preoperative and pathohistological resect findings in 127 patients with subvesical obstruction who underwent transurethral resection of the prostate as a standard procedure in the University Hospital of Split in the period between 2019 and 2021. Data were collected from the Hospital Information System and patient medical history. Results: There is no significant age difference between subjects with inflammation and without inflammation. Subjects with inflammation had statistically significantly higher PSA levels (P<0,001), and the median PSA level in subjects with inflammation was 6,02 ng/ml while the median PSA level in subjects without inflammation was 2,82 ng/ml. Subjects with elevated PSA were more likely to develop inflammation (90,7%) compared to subjects without elevated PSA (63,5%) (P<0,001). The incidence of inflammation is 5,6 times higher in patients diagnosed with elevated PSA compared to patients without elevated PSA (P<0,001). Conclusion: Inflammation in the pathohistological finding is not more common in elderly patients. Subjects with inflammation in the pathohistological finding have a higher level of total PSA compared to subjects without inflammation. Subjects with elevated PSA are more likely to develop inflammation than subjects without elevated PSA and have a higher chance of developing inflammation than subjects without elevated PSA.