Stem cell factor (SCF) is a cytokine that stimulates development of erythroid precursors and, consequently, may have potential importance in the treatment of certain anemias. We report a case of a young woman with Diamond-Blackfan anemia who received SCF treatment. One effect of SCF treatment is cutaneous hyperpigmentation at the injection site. In contrast to previously reported cases of patients who had fewer SCF injections, her hyperpigmentation was extensive and of major cosmetic concern. SCF may play a role in a number of disease processes. This case demonstrates the need to consider the potential pigmentary side effects of SCF therapy and to make careful selection of the injection sites.