Urticaria affects 15–25% of the population once in their lifetime. Also 0.5-1% of the population suffers from the idiopathic chronic urticaria. More than 80% of chronic urticaria is idiopathic. 24% of the world’s population are infected with soil-transmitted helminth infections worldwide. Toxocara canis is associated with urticaria. To determine T.canis IgG antibody in patients with idiopathic chronic urticaria. Materials and methods: The study was a case-control study. There were enrolled 40 patientswith confirmed diagnosis of idiopathic chronic urticaria (ICU) at National Dermatology Center and 60 controls without any skin diseases between the ages 12-64 years. Blood samples were tested using an enzyme linked immunosorbent assay (ELISA) technique for the detection of IgG specific antibodies to T.canis excretory-secretory (TES) antigens (Ridascreen® toxocara IgG).15% of urticaria patients were male, 85% were female and the mean age was 34,50±14,36. 18.3% of healthy control groups were male, 81.7% were female and the mean age was 39,77±11,24. 32.5% (13/40) of patients presenting with ICU had positive results to TES-ELISA. About control group: 5% (3/60) were positive TES-ELISA serology result. The pet-keeping history gave the following results: 48% of urticaria patients and 55% of control patients were in possession of dog; this difference was no significant (p>0.1). Our data show that T.canis is one of the etiologic factor in patients with ICU (p=0.001, OR (95% CI)=9.148 (2.404-34.808). The analysis of risk factors evidenced that the presence of dogs within the houses and household location showed no significant association with T.canis infection (p>0.1).