Real time ultrasound technology is basically performed by three different techniques: transabdominal sector scan; transrectal radial scan, and transurethral radial scan. This review, based on 7 years of experience on more than 2,500 patients, compares the usefulness and limitations of these techniques in the diagnosis of lower urinary tract pathology. Transabdominal ultrasound is used for general evaluation of the lower urinary tract and the determination of residual urine. Transrectal ultrasound determines prostatic mass, diagnoses early prostatic cancer and evaluates exact staging of prostatic cancer and pathology of the seminal vesicles. Transurethral ultrasound is the best technique for preoperative staging of bladder cancer.