The authors present a case of in situ ductal carcinoma of the breast (DCIS) with no associated mass in a 46-year-old woman examined with Tc-99m MIBI and Tc-99m(V) DMSA scans, which were acquired in separate sessions 10 minutes and 60 minutes after injection. Histologic analysis revealed a small (<1 cm) infiltrating ductal carcinoma located within the DCIS. Mammography showed a cluster of microcalcifications on a very dense parenchymal background. Tc-99m(V) DMSA was characterized as positive for DCIS, especially in the delayed image. Tc-99m MIBI failed to identify the lesions previously noted. In conclusion, Tc-99m(V) DMSA scintimammography seems to have an advantage and could improve the detection of nonpalpable in situ breast carcinomas.