Low-dose weekly methotrexate therapy has been used to treat patients with psoriasis for more than 20 years. This regimen has also been used to treat rheumatoid arthritis, inflammatory bowel disease, primary sclerosing cholangitis, and corticosteroid-dependent asthma. We report two patients with Behçet's disease with cutaneous neutrophilic vascular reactions and three with cutaneous polyarteritis nodosa who responded dramatically to low-dose weekly methotrexate therapy.