Florid reactive periostitis is a rare benign bone lesion that occurs most often in the phalanges of hands and feet. Histologic evaluation is commonly required to distinguish this benign lesion from clinically indistinguishable malignant and infectious disorders. The lesion is typically self-limiting or cured by local excision; however, in very aggressive cases ray amputation may be indicated. The authors report a case of florid reactive periostitis affecting the thumb with satisfactory outcome and without recurrence at 2-year follow-up.