Splenic metastasis of solid tumors is a rare event, most often diagnosed at the time of autopsy. Whereas in cases of widely disseminated cancer, splenic involvement may be fairly common, solitary splenic metastasis in the absence of other metastases is exceedingly rare. The authors report a case of a 63-year-old woman in whom the sole detectable distant metastasis of a lung carcinoma was a splenic mass. The splenic lesion was detected before the resection of the primary lung lesion during a complete metastatic work-up. At that time, however, it was considered unlikely that the mass in the spleen represented a metastasis because of the lack of metastatic disease elsewhere.