OBJECTIVE. We aimed to evaluate whether chest CT alone is sufficient for follow-up assessment of patients with primary mediastinal B-cell lymphoma that is in remission. MATERIALS AND METHODS. A retrospective review of medical records and CT examinations of patients who received a diagnosis of primary mediastinal B-cell lymphoma between January 1989 and January 2000 was performed. The first-year follow-up comprised examinations at 3-month intervals of the neck, chest, abdomen, and pelvis, with the examination modality alternating between CT and gallium scintigraphy. Patients who achieved complete remission underwent the same CT protocol twice the following year and then once a year during sequential follow-up. RESULTS. Fifty-three patients with primary mediastinal B-cell lymphoma at presentation-31 females and 22 males, ranging in age from 17 to 61 years (average age at diagnosis, 34 years)-were studied. The follow-up time ranged from 6 to 143 months (average follow-up time, 42.4 months). Although 11 of the patients had only a partial remission, 42 patients (79%) achieved complete remission, with one patient lost to follow-up and thus excluded from study. Recurrence was diagnosed in six of these 42 patients. All six had mediastinal recurrence with additional involvement of the lungs, chest wall, pericardium, and pleura. One patient also had bone marrow involvement at recurrence. CONCLUSION. Recurrence of primary mediastinal B-cell lymphoma in patients who achieve complete remission appears to be confined to the chest. Consequently, chest CT alone is sufficient for routine follow-up of these patients.