Cow's milk allergy (CMA) is nowadays a common problem in Thai children. We reviewed medical records of patients with CMA from the Department of Pediatrics at King Chulalongkom Memorial Hospital of the past 10 years, from 1998 to 2007. The criteria for the diagnosis of CMA included: elimination of cow's milk formula resulting in improvement of symptoms, and: recurrence of symptoms after reintroduction of cow's milk by oral challenge or by accidental ingestion. Of the 382 children with a diagnosis of CMA, 168 were girls and 214 were boys. The average age at the time of diagnosis was 14.8 months (7 days-13 years). The average duration of symptoms before diagnosis was 9.2 months. A family history of atopic diseases was found in 64.2% of the patients. All of the mothers reported an increased consumption of cow's milk during their pregnancy. The most common symptoms were respiratory (43.2%) followed by gastrointestinal (GI) (22.5%) and skin manifestations (20.1%). Less common symptoms included failure to thrive (10.9%), anemia (2.8%), delayed speech due to chronic serous otitis media (0.2%) and anaphylactic shock (0.2%). A prick skin test with cow milk extract was positive in 61.4%. Exclusively breast-fed was found in 13.2% of the patients. Successful treatment included elimination of cow's milk and milk products and substitution with soy formula in 42.5%, partial hydrolysate formula (pHF) in 35.7%, extensive hydrolysate formula (eHF) in 14.2%, and amino acid formula in 1.7%. Continued breast feeding was successful in 5.9% (with maternal restriction of cow's milk and milk products). Our study demonstrates the variety of clinical manifestations of CMA in Thai children especially respiratory symptoms which are usually overlooked.