Five cases of hematogenous osteomyelitis of the ischiopubic synchondrosis (IPS) were encountered among 180 patients with osteomyelitis treated over a 5-year period. Symptoms were poorly localized in all these IPS osteomyelitis patients. The IPS can normally show expansion and irregular mineralization radiographically and focal hyperconcentration of radiophosphates on scintigrams. Findings are frequently asymmetrical negating comparison with the contralateral side. In the cases of osteomyelitis, radiographs were abnormal at the time of presentation in only one of these five cases. In two of the four patients who had radionuclide bone scans, activity at the IPS exceeded that seen in a normal control population, but all showed loss of definition of the IPS and regional increased uptake permitting an early diagnosis.