The increased incidence and awareness of prostate cancer, together with developments in treatment, has generated a significant need for appropriate imaging to detect and stage the tumour initially, guide radiotherapy delivery and monitor disease on follow-up. Transrectal ultrasound is usually the first imaging investigation, and its role is primarily to guide prostate needle biopsy. It also has an established role in imaging-guided treatments, such as brachytherapy. Magnetic resonance imaging has developed considerably in recent years, and is now the principal staging investigation before treatment. Innovations in functional and biological imaging of the prostate will, in the future, contribute valuable information to support parallel developments in radiotherapy techniques for prostate cancer. The ultimate goal is a coordinated diagnostic and therapeutic approach to individualise and optimise the treatment plan for patients with prostate cancer.