In-111 chloride imaging was used in the evaluation of a patient with Type I Gaucher's disease before splenectomy for pancytopenia. This case is the first report of its use in this clinical setting. The image demonstrated the presence of adequate marrow reserve, thereby suggesting that the pancytopenia was due to hypersplenism rather than marrow replacement. Normalization of blood counts after splenectomy confirmed this interpretation. Eight months later, the patient had acute pain in the left knee. Bone imaging suggested a left lateral tibial plateau fracture that was not seen on plain radiographs or magnetic resonance imaging, but was confirmed by x-ray tomography. The significance and implications of these findings are discussed.