Introduction. Currently, the appropriate number of fragments obtained during a prostate biopsy in order to detect early histological changes in the prostate tissue is constantly debated. Aim of the study. To reveal the correlation between the PSA value and the number of biopsies required to be performed for the detection of prostate cancer. Materials and methods. The study was conducted on the basis of 52 ultrasonography-guided prostate biopsies performed between May 2016 - March 2017. The case-control, retrospective study involved evaluating the results of the 52 biopsies, of which 13: 6-core and 39: 12-core. The Transrectal Ultrasound-guided Prostate Biopsy (TRUS) was performed according to the National Clinic Protocol with the main indication being the level of PSA higher than 4 ng/ml and taking into consideration the contraindications and possible complications that may occur. For statistical data processing SPSS program was used, applying descriptive and comparative statistical analysis. Results. Patients that underwent the biopsy aged between 52 and 88 years, and PSA varied between 2.81 and 177.00 ng/ml with an average of 89.90 ng/ml. In 22 patients (42.30%) of the group of subjects who underwent the biopsy, the morphological clinical picture of adenocarcinoma was found, and in 30 patients (57.69%) – benign prostatic hyperplasia. In none of the patients any major complications have occured. In patients with 6-core biopsy were detected 8 Benign Prostatic Hyperplasia (BPH) with the average PSA value – 34.98 ng/ml, the minimum being 7.74 ng/ml and maximum – 10.0ng/ml. Those with 6-core biopsy and adenocarcinoma (5) had an average PSA of 69.04 ng/ml, the minimum being 14.0 ng/ml and maximum – 177.0 ng/ml. In patients with 12-core biopsy were detected 22 BPH with the average PSA value of 14.19 ng/ml, the minimum being 2.81 ng/ml and maximum – 44.0 ng/ml. Those with 12-core biopsy and adenocarcinoma (17) had an average PSA of 46.0 ng/ml, the minimum being 9.59 ng/ml and maximum – 140.0ng/ml. Thus, there is a direct interrelation between the increase of PSA levels in serum and the detection of adenocarcinoma. Even though, this marker is not totally effective in detecting the PC, which implies the need to use ultrasound-guided biopsy, it has a direct influence on electing the number of the samples essential for the detection of the PC. Conclusions. Although the main method of diagnosis is considered to be 12-core biopsy, it loses its purpose in cases with PSA higher than 44 ng/ml when the 6-core biopsy has the same revelatory properties and is less invasive.