The evaluation of patients with blunt renal trauma has become controversial. We tested the hypothesis that renal contusion can be diagnosed clinically and that these patients do not require radiographic evaluation. To evaluate the association of microhematuria without shock and with renal contusion, we reviewed the medical records of 831 patients with hematuria following blunt renal trauma. Microscopic hematuria without shock was noted in 160 of 241 patients without and 334 of 590 with associated injuries. Of the former 160 patients 159 had renal contusion and 1 had a renal laceration, while of the latter 334 patients 329 had renal contusion, 3 had renal laceration, 1 had renal rupture and 1 had a pedicle injury. Most patients with microscopic hematuria and no shock after blunt renal trauma had a renal contusion, especially those with no associated injury. All of the patients with renal contusions experienced no complications from nonoperative management. However, avoiding a radiographic evaluation in patients with blunt renal trauma plus microhematuria and no shock would miss a few cases of severe renal injury.