A retrospective review of radiology registry identified 3 cases of diagnosed giant multilocular cystadenoma of prostate. The first case illustrates a 59-year-old man with worsening voiding and storage symptoms of 2 months duration. The prostate was enlarged with the right lobe being bigger than the left node and his PSA was 9.3 ug/l. MRI showed large Multi cystic mass from the prostate and TRUS biopsy revealed adenocarcinoma prostate. Neoadjuvant LHRH agonist shrunk the mass before radiotherapy. He has no urinary symptoms and PSA consistently less than 0.1. Repeat MRI showed highly shrunken mass. In the second case, we present a 79-year-old patient presenting with rising PSA despite being on finasteride. MRI diagnosed large cystic and solid mass arising from the prostate and extending to the abdomen. Tran’s rectal ultrasound guided biopsy plus aspiration of the fluid from the multiloculated cyst revealed benign cystic adenoma with no evidence of any malignancy. Repeat MRI after 6 months of LHRH agonist showed multiloculated cyst adenoma of the prostate appears stable with no significant reduction in size and his PSA remains high. The third case is an 83-year-old presenting with LUTS, haematuria and rising PSA. He has a past medical history of low grade prostate cancer (diagnosed at TURP). MRI scan showed an enlarged echogenic prostate. TRUS biopsy of the mass identified complex proliferation of atypical glandular epithelium in a rather villous adenomatous pattern. Neoadjuvant LHRH agonist showed reduction in lower urinary symptoms.