Research objectives: The objectives of this study were to investigate the expression and the expression intensity of immunohistochemical markers CK HMW and p63 in prostate samples with the findings of hyperplasia of basal cells and PIN compared to the intensity of expression of prostate surrounding normal tissue, and to determine whether there is a difference in the intensity of expression of these markers between said entities. Then, compare the expression intensity of immunohistochemical markers AMACR with the PIN, ASAP and prostate adenocarcinoma, and examine the expression and the expression intensity of the immunohistochemical marker c-myc between prostate samples with the findings of ASAP, PIN and prostate adenocarcinoma. Study design: A cross-sectional study, with historical data. Materials and methods: The material is prostate tissue samples archived in the Clinical Institute for Pathology and Forensic Medicine of the Clinical Hospital Centre Osijek in a one year period, which have diagnosed changes in PIN, ASAP, HBS, as well as a prostate adenocarcinoma. The samples were previously processed by standard histochemical procedure and dyed with Hematoxylin-Eosin (HE), and immunohistochemical methods with markers CK HMW, p63, AMACR and c-myc. The expression and intensity of expression of these markers were investigated by the Leica DMS light microscope. Results: Most of the adenocarcinoma diagnosed belongs to group grade 2. There was a statistically significant difference in the intensity of expression of markers CK HMW and p63 between PIN and normal prostate tissue, and between HBS and normal prostate tissue. 17 participants (29.3%) had a strong intensity of expression of the marker AMACR in adenocarcinoma, and 20 participants (43.5%) had a strong intensity of expression of the marker c-myc in adenocarcinoma. Conclusion: Immunohistochemical methods were performed on all samples, what indicates its great help in differential diagnosis of various pathological prostatic changes.