To investigate the role of the IVP, we studied 139 patients with blunt abdominal trauma and hematuria. Multivariate analysis of clinical parameters was utilized in attempt to predict which patients would have abnormal IVP's and which would eventually require genitourinary operation. Thirty-four patients (25%) demonstrated abnormalities on IVP; however, no combination of clinical findings (including degree of hematuria) could reliably predict which patients would have abnormal IVP's. On the other hand, in 90% of the patients, the necessity for genitourinary operation could be reliably predicted based on: presence of blood at the urethral meatus, degree of hematuria, patient age, Injury Severity Score, and number of rib fractures. We conclude that to detect IVP abnormalities, IVP's need to be performed on all blunt trauma patients with hematuria. However, patients likely to have injuries requiring operative repair can be predicted. Those patients unlikely to have genitourinary injury requiring repair, therefore, may have IVP performed on a nonurgent basis.