Background: This original cohort of patients with erythrodermic cutaneous T-cell lymphoma (CTCL) was reported to have clinical improvement with photopheresis during the 12 months of the original study. No long-term follow-up data have been available to examine the impact of this therapy on the disease. Objective: Our purpose was to provide long-term follow-up on the original 29 erythrodermic CTCL patients treated with photopheresis and to compare these results with historical controls. Methods: Files of patients from the original photopheresis study centers were reviewed and their current status was documented. Results: The median survival of the treated patients was 60.33 months from the date of diagnosis and 47.9 months from the date of the start of photopheresis therapy. A complete remission has been maintained in four of the six patients who achieved complete responses in the original study. The best responses were seen in patients with a lower CD4/CD8 ratio in the peripheral blood at the start of therapy. Conclusion: Photopheresis can influence the natural history of erythrodermic CTCL by inducing remissions and prolonging survival with minimal toxicity.