Prostate mucinous adenocarcinoma with signet ring cells(MCSRC)is a rare morphologic variant of prostate cancer,with only 12 cases reported to date.[1] Diagnosis of this carcinoma requires that at least 25% of the tumor tissue should consist of an extracellular mucin pool.[2] In this report, we present a case of prostate prostate mucinous adenocarcinoma with signet ring cells.