Background: Chronic urticaria (CU) is the recurrence of erythematous itching papular skin lesions for at least 6 weeks. Although it is often considered a benign condition, there are reports of the association of chronic idiopathic urticaria with infections, thyroid disease, foods, medications, autoimmunity, neoplasms, and low serum level of vitamin D. We aimed to identify the effect of lifestyle characteristics, environmental factors, family history, and specific comorbidities as potential external eliciting factors on the onset of chronic urticaria. Materials and Methods: The present research was conducted on 141 adult patients diagnosed by CU at the allergy clinics of Azad University hospitals in Tehran from January 2021 to January 2022. A questionnaire on different life events during the past 3 months before the onset of urticaria was developed to evaluate the characteristics of the patients with chronic urticaria. Meanwhile, 58 healthy individuals who were similar to the patients in terms of age range and gender were asked to participate in the study as the control group. Results: The mean age of the patients and the controls were 41.7 years and 39.8 years, respectively. The female and male patients were 105(74.47%) and 36(25.53%), respectively. Only two of the evaluated predisposing factors were meaningful including the use of new medications (23.4% versus 19%; P=0.006) and the co-existence of anxiety and depression (14.1% versus 4%; P=0.036). Conclusion: Among the different factors evaluated in this study, only two were found to be significant in relationship with CU which are anxiety/depression and medications.