Ultrastructural studies have shown a wide morphological diversity of neuroendocrine cells (NEC), which is correlated with a large number of known secreted into the blood substances, including neuron-spesific enolase, chromogranin A (СgA), chromogranin B, bombesin, serotonin, somatostatin, thyroid-stimulating hormone like peptide, parathyroid hormone-related peptide, calcitonin. It is believed that the NEC in varying amounts are always present in prostate cancer (PC). This is due to the large number of endocrine and paracrine cells of the prostate gland compared to any other organ of the genitourinary system. In some cases, prostate cancer completely controlled by neuroendocrine cells, such as small cell PC. The prognostic significance of neuroendocrine differentiation in prostatic malignancy is controversial, but the results of recent studies with markers such as CgA suggest that neuroendocrine differentiation (NED), as reflected by increased tissue expression or blood concentrations of these neuroendocrine secretory products, is associated with a poor prognosis, tumour progression, and androgen independence. One of the most commonly used marker of NED PC is CgA. It is considered that this marker has a high sensitivity and specificity in determining the NED PC. From publications review it is clear that CgA is of high interest for the early detection PC. Also this marker is very promising in detection of aggressive forms of prostate cancer. Along with such standard tests like the PSA level, Gleason score, number of positive cores, NED definition of the tumor may be necessary for the analysis of a comprehensive approach to PC treatment selection.