To determine which clinical or laboratory criteria best reflected the prognosis for 83 children with acute hematogenous osteomyelitis (AHO), they were compared with outcomes after a follow-up of at least 2 months (for 78%, > or = 6 months). Twenty-eight children (34%) developed sequelae. They had higher serum C-reactive protein (CRP) concentrations (days 1-6 of treatment; P = .0004 to .0001) and higher clinical scores (P = .0001) than did patients who had an uneventful recovery. The frequency of sequelae increased from 3% to 73% (P = .0001) when CRP concentrations exceeded the defined cutoff limits and the clinical scores were > or = 1. Age, the duration of symptoms at diagnosis, and the type and duration of intravenous antimicrobial therapy or surgical management did not differ (P > .05) between children with and without sequelae. Both CRP determinations and clinical evaluations with use of a scoring system enable early detection of sequela-prone AHO in children and are most accurate when used together.