Mycosis fungoides is a cutaneous T-cell lymphoma, a subgroup of non-Hodgkin's lymphomas, characterized by skin infiltration and occasionally systemic involvement. The association of pregnancy and mycosis fungoides has not been described previously. A case of mycosis fungoides, stage IVb, in a pregnant woman is reported. Prior to pregnancy, the patient received adriamycin, cyclophosphamide, vincristine prednisolone (CHOP) and bleomycin and total body irradiation. Around the concepcional period she presented a cutaneous relapse palliated with photon radiotherapy. No obstetrics complications were observed during gestation. At 39 week's gestation a cesarean section was performed and a healthy 2900 g boy was delivered. Mycosis fungoides did not worsen during pregnancy and postpartum period. In conclusion mycosis fungoides did not adversely affect pregnancy outcome and gestation did not worsen the malignancy course. This case report may be valuable in managing patients with mycosis fungoides who are currently pregnant or are contemplating pregnancy.