Posttraumatic osteomyelitis was investigated in 23 patients using nuclear medicine techniques. Tc-99m hexamethylpropilene amine oxime (HMPAO)-labeled leukocyte scintigraphy was performed in 11 patients, and Tc-99m nanocolloid scanning was performed in the other 12 patients. The scintigraphic findings were compared with clinical, laboratory, radiologic, and bacteriologic results. The findings on leukocyte imaging were consistent with the clinical symptoms in 7 of 11 patients, with the laboratory pattern in 7 of 10 patients, with the radiologic findings in 7 of 11 patients, and with the results of bacteriology in 6 of 7 patients. The findings on nanocolloid scintigraphy corresponded with the clinical symptoms in 9 of 12 patients, with the laboratory pattern in 8 of 10 patients, with the radiologic findings in 8 of 12 patients, and with the bacteriology in 4 of 5 patients. The results suggest that both methods were of similar value for the detection of chronic posttraumatic osteomyelitis regardless of whether the process was active. Conversely, on the basis of semiquantitative analysis of the images, leukocyte scintigraphy seemed to characterize the grade of inflammation better than did nanocolloid scintigraphy.