Extracorporeal photopheresis (ECP) is a therapeutic procedure in which leukapheresed peripheral blood mononuclear cells are exposed to ultraviolet A in the presence of the photosensitizer 8-methoxypsoralen and then reinfused. Several guidelines recommend ECP as a treatment of choice in erythrodermic primary cutaneous T-cell lymphomas (E-CTCL). However, the level of evidence is low due to the rarity of this disease and the lack of randomized controlled trials. We performed a review of the English literature, restricting our analysis to studies including erythrodermic patients and more than 10 cases. Based on these criteria, we identified 28 studies, with a total of 407 patients. The median response rate in erythrodermic patients was 63% (range 31–86%), with a complete response rate ranging between 0 and 62% (median 20%). In our experience, we treated 51 patients with E-CTCL since 1992. A clinical response was obtained in 32 of 51 patients (63%), with a 16% complete response rate. The median time for response induction was eight months (range: 1–23). The median response duration was 22.4 months (range six months to 11 years). The treatment was generally well tolerated without systemic toxicities grade III–IV. The pretreatment parameters significantly associated with a higher likelihood to obtain a clinical response were the B-score in the peripheral blood, CD4/CD8 ratio, and amount of circulating CD3+CD8+ cells. Literature data together with our personal experience clearly support the clinical activity and tolerability of ECP in patients with E-CTCL. Prospective controlled clinical trials are strongly recommended to better document the evidence.