A varicella infection in a previously healthy young girl was complicated by bacterial sepsis, arthritis, and osteomyelitis in multiple locations. This secondary complication caused by Staphylococcus aureus was associated with a transient defect in granulocyte function and an alteration in the representation of CD4 and CD8 positive lymphocyte subpopulation. The mechanism responsible for secondary bacterial infections following varicella may be due to transient defects in granulocyte function.