Purpose To report a case of orbital lymphoma with systemic dissemination that was identified and localized by combined positron emission tomography (PET)/computed tomography. Design Case report. Methods A 75-year-old woman presented with a 6-month history of painless, progressive fullness of her right upper eyelid. A PET/computed tomography was obtained to provide functional and anatomic assessment of the orbits. An orbitotomy was performed with sub-total excision of the lesion to obtain histologic diagnosis. Results The PET/computed tomography scan revealed intensive uptake of tracer in a right orbital mass measuring 2.3 × 1.8 × 2.6 cm. Foci of abnormal tracer uptake were also noted in the right neck, right hilar region, and central abdomen. Histopathologic findings were consistent with follicular cell lymphoma. Conclusions The combination of PET/computed tomography provides accurate and precise information in an expedited manner not offered by alternative imaging modalities. PET/computed tomography imaging should be considered in the evaluation of orbital neoplasms, especially if lymphoma is suspected.