Methotrexate is used to produce regression in a wide range of neoplastic conditions, including acute leukaemias, non-Hodgkin's lymphoma, soft tissue and osteogenic sarcomas and solid tumors particularly breast, lung, head and neck, bladder, cervical, ovarian and testicular carcinomas. Methotrexate is of value in the treatment of psoriasis but because of the risks associated with this use, it should only be given when the disease is severe and has not responded to other forms of treatment.