Even though the diagnosis of cancer prostate can usually be made onmorphologic features such as growth pattern, nuclear atypia and the absence of basalcells, it is sometimes difficult to reach a firm diagnosis by routine histological study, inparticular for small foci of cancer in needle biopsies. Many benign conditions can mimicprostate cancer,therefore, the application of immunohistochemistry to distinguish prostatecancer from benign mimickers and to confirm the diagnosis becomes helpful andnecessary, especially in equivocal cases. A retrospective study done on 74 cases of prostatic lesions diagnosed at SurgicalPathology Department, National Cancer Institute (NCI) from 2007 to 2013.Parrafin blocks of a total of the cases including (cancer prostate, BPH&ASAP) were cutfor Hx&E assessment &IHC staining (AMACR &HMWCK). AMACR sensitivity & specificity results were 90.2% &100%, respectively, whileHMWCK sensitivity & specificity results were 86.2% & 100%,respectively.Usage ofboth markers, simultaneously gave the best results (100% sensitivity & specificity ). Using immunohistochemical studies have become very important in diagnosingchallenging prostatic lesions, like PIN & ASAP. AMACR expression had no correlationwith Gleason score or perineural invasion, thus the intensity of expression bears nocorrelation to bad prognostic signs of prostatic cancer, however studying prognosticimpact of AMACR should be further validated by future studies It seems that AMACRplays a role in carcinogenesis of prostatic cancer being expressed in PIN.