The appearance of several unusual tumours in the prostate has resulted in questions being raised concerning their histogenesis; moreover, some of these tumours have prognoses that are quite unlike those of prostatic adenocarcinoma. Unusual neoplasms involving the prostate have been described in recent years, including mucinous cystadenocarcinoma, neuroendocrine cancer, lymphoma, spindle cell neoplasm, squamous cell carcinoma and transitional cell carcinoma. Radiological findings can overlap, and play limited roles in the diagnoses of these entities. However, knowledge of the radiological findings in these conditions can be helpful in making differential diagnoses. Images of prostate lesions using several imaging modalities, including transrectal ultrasound, MRI and CT, as well as available pathological images of such lesions, are presented in this article.