Cold urticaria is defined as a urticarial and/or angioedematous reaction of the skin to contact with cold objects, water or air. Types of urticaria associated with infectious diseases, such as mononucleosis, rubeola, varicella, syphilis, hepatitis, and HIV infection have been reported. We present the case of a patient who developed cold urticaria associated with acute serologic toxoplasmosis. The patient was a 34-year-old man who for the previous 2 months had presented cutaneous pruritus accompanied by several papular lesions in parts of the skin exposed to cold as well as those in contact with cold water. The result of an "ice-cube test" was positive. Serologic tests for Toxoplasma gondii showed an IgG level of 68 UI/ml and were positive for IgM, while a test for cryoglobulins was positive. One month later cryoglobulins were negative and a serologic test for T. gondii showed an IgG concentration of 75 UI/ml and positive IgM. Three months later cryoglobulins were still negative, IgG for T. gondii was 84 UI/ml, and IgM was positive. After 6 months cryoglobulins were still negative, IgG level was 68 UI/ml and IgM was still slightly positive. In the final evaluation, 14 months later, IgG level was 32 UI/ml and IgM was negative. The patient continues to present clinical manifestations of cold urticaria, although he has experienced some improvement and his tolerance to cold has increased after treatment with cetirizine.