Histologic or cytologic verification of the diagnosis is mandatory. In the majority of cases the tumour originates in the peripheral portion of the gland. It is often multifocal. Perineal puncture biopsy and transrectal aspiration biopsy are of equal value to verify the diagnosis and establish the malignancy grading. Palpation is rather accurate to detect extraprostatic tumour growth but not to evaluate the tumour extension within the gland or the occurrence of multifocal tumour. Of the modern imaging techniques transrectal ultrasound scanning appears superior to visualize small or multifocal tumours.