Human neonates [21] suspected of having acute osteomyelitis were studied by 99mTc phosphate radiopharmaceuticals. Of the 10 infants, subsequently proven to have osteomyelitis involving 20 sites in all, only 6 sites (31.5%) were abnormal by bone imaging; 58% were normal and 10.5% equivocal. These poor results are contrary to the high accuracy rate achieved in slightly older infants. The bone scan cannot diagnose neonatal osteomyelitis.