Transrectal ultrasonography (TRUS) of the prostate has been used for screening and staging of prostate cancer since the first practical tomogram of the prostate was obtained in Japan. Systematic biopsy of the prostate in men with elevated prostate specific antigen (PSA) has been a gold standard method for the detection of prostate cancer while the ability of conventional gray-scale imaging was limited to differentiating malignant from benign lesions. In this review, we discuss recent developments in TRUS. Contrast-enhanced Doppler imaging as well as elastography are new ultrasound technological modalities that improve cancer detection and may lead to new diagnostic approaches for prostate cancer. Furthermore, real-time TRUS navigation and augmented reality have been developed for minimally invasive surgery such as minilaparotomy and laparoscopic radical prostatectomy. Intra-operative TRUS visualizes the surgical anatomy and cancer lesion and may help surgeons perform precise operations. Recent advances in TRUS potentially improve the diagnostic performance and therapeutic outcome for prostate cancer.