Background: Urticaria is an allergic skin disorder characterized by wheals. Though the diagnosis is easy, it is difficult to identify the cause for the episodes. Autologous serum skin test (ASST) and skin prick test (SPT) help in the identification of the cause. The objective of the study was to determine the frequency of ASST and SPT positivity in patients with chronic idiopathic urticaria (CIU).Methods: Fifty-six patients attending the dermatology OPD with chronic idiopathic urticaria were evaluated and taken up for the study. ASST and SPT were performed on all the patients and the obtained results were documented. Data was analyzed using Chi square test.Results: Among the 56 patients studied, males (53.57%) outnumbered females and the majority was in the age group 21 to 30 years (33.9%). One third of the study patients gave history of known food allergy and 10.7% gave history of dust allergy. ASST positivity was seen in 30.3% and SPT positivity was seen in 64.3%. Ten of our patients (17.8%) were positive to both ASST and SPT. Amongst the SPT positives 33.3% showed positivity to food allergens, 19.4% showed positivity to aeroallergens and 47.2% showed positivity to both. Conclusions: ASST and SPT are two reliable tools in identifying the cause for urticaria and this in turn helps in avoidance of possible causes and providing proper treatment.