Background: Allergy to cow’s milk is the most common food allergy in infant and young children. Symptoms of a milk allergy reaction can be mild like rash or severe, such as anaphylaxis. The aim of this study was to assess the value lactalbumin and lactog lobulin specific IgE in diagnosis of cow`s milk protein allergy. Design and Methods: This study was carried on 70 subjects classified into the following groups: Group 1: Include 50 patients with suspected cow milk protein allergy. Diagnosed by presence of chronic diarrhea with history of recent introduction of cow milk and positive elimination test. Group 2: Include 20 ages and sex matched apparently healthy subjects, their ages were ranged between (8-18) months. All individuals included in this study were subjected to full history taking, clinical examination, complete blood count and determination of serum total IgE, lactoglobulin and lactalbumin specific IgE which were carried out by ELISA technique. Results: The diagnostic accuracy of lactoglobulin IgE in diagnosis of protein allergy was (84%), with sensitivity (78%), specificity (100%), positive predictive value (100%) and negative predictive value (65%) at cutoff point of 0.345 IU/ml. While, the diagnostic accuracy of lactoalbumin IgE in diagnosis of protein allergy was (83%), with sensitivity of (84%), specificity (80%), positive predictive value (91%) and negative predictive value (67%) at cutoff point of 0.335 IU/ml. Conclusions: Lactalbumin and lactoglobulin specific IgE assay are important in diagnosis of cow milk protein allergy and their combination may give better diagnostic accuracy than total IgE assay..