Scintigraphy with 67Ga-citrate indicated the transition of an orbital pseudotumor into a lymphoma by a distinct increase in 67Ga avidity. The patient initially presented with a pseudotumor in the right orbit that was verified by CT and MRI. It was caused by a chronic reactive lymphocytic inflammation extending from the lacrimal gland. At that time, scintigraphy was negative. Six and a half weeks later, the tumor had not responded to therapy and scintigraphy then showed a striking increase in gallium avidity. Consequently the tumor was excised and histology ultimately revealed a high-grade non-Hodgkin's T-cell lymphoma.