Unicameral bone cysts have been treated by a variety of methods including nonoperative treatment, bone packing, and methylprednisone acetate injection. This article reviews the methods of treatment and classification of unicameral bone cysts. Three calcaneal unicameral bone cysts were injected with methylprednisone acetate and were followed for 8 to 32 months. Two unicameral bone cysts were unresponsive to methylprednisone acetate and were classified as "persistent." One unicameral bone cyst was moderately responsive and was classified as "incompletely resolved."