Background Recent reports have suggested that gastroesophageal reflux disease (GERD) is link with cow’ s milk (CM) sensitization in children. The aim of this study was to determine the frequency of CM sensitization in young children with GERD. Materials and Methods This cross-sectional study included 33 children (median age, 2. 93± 1. 90 years) with GERD according to a valid gastroesophageal reflux questionnaire, and 33 healthy children (median age, 3. 39± 1. 90 years). CMA was diagnosed by skin test, serum specific immunoglobulin E level and atopy patch test to milk in both patient and control groups. Results Twenty-four children with GERD were positive for at least one of the diagnostic tests for CM sensitization compared to 13 children in control group (odds ratio [OR] = 1. 78; 95% confidence interval [CI]: 1. 14 to 2. 80). Unlike the results of skin prick tests and specific Immunoglobulin E (IgE) levels to milk which showed no difference between children with GERD and healthy controls, there was a significant difference in the results of patch test (OR=2. 06; CI95%: 1. 46 to 2. 91). Conclusion Based on our results, CM sensitization is 1. 7 higher in children with GERD than non-GERD children. Patch testing preferably would better to perform for diagnosis of CM sensitization in those children with GERD.