We have synthesized two water soluble dendritic porphyrins, termed DP1 and DP2 and have successfully radiolabeIed them with Tc-99m. These Tc-99m-labeled porphyrins were administered to C-6-glioma tumor bearing Wistar rats and scintiimaging and biodistribution studies were carried out. Tumor to muscle ratios of DP1 and DP2 were 8.0 and 9.7, respectively. These molecules may have potential for tumor imaging and diagnosis and may even prove useful as photosensitizers in photodynamic therapy applications.