Acute hematogenous calcaneal osteomyelitis characteristically affects children. A recent trend has emerged toward shorter courses of antibiotics. In our randomized, prospective treatment trial of children aged 3 months to 15 years, the intravenous antibiotic (clindamycin or a first-generation cephalosporin) was given only for the first 2 to 4 days and the remainder of the 20- to 30-day course was completed orally. A bone sample for culture was to be taken routinely, but all additional surgery was performed on special demand. We performed a retrospective subanalysis of cases affecting the calcaneus. The follow-up period was 1 year. Of the 14 participants enrolled, 11 completed the 1-year follow-up period, and their data were analyzed. Staphylococcus aureus was the cause of 10 cases; all strains were methicillin sensitive. The median intravenous treatment duration was 3 days. Four patients required open incisional trepanation (trephination). All participants attending the 1-year follow-up examination had fully recovered. The outcome of calcaneal osteomyelitis caused by methicillin-sensitive S. aureus in a child will be good, if the patient seeks treatment early and antibiotic therapy is started promptly. A bone biopsy is needed to obtain a representative sample for bacteriology. (C) 2015 by the American College of Foot and Ankle Surgeons. All rights reserved.