Although milk allergy may appear at any age, it is principally a problem of early childhood that has its onset mostly during infancy. Allergy to milk may manifest variety of symptoms and signs with multiple organ involvement. Because the symptoms are mostly nonpathognomic, the diagnosis of milk allergy is often mistaken, being likely to be overdiagnosed or underdiagnosed. Milk allergy in infancy most frequently affects the gastrointestinal tract, followed by the respiratory tract, then the skin. The mainstay of treatment of any allergy is avoidance. But, approximately 20-35% of patients with milk allergy are also allergic to soy preparations. Therefore patients being evaluated for milk allergy should concern about soy protein corss-reactivity. We experienced 4 months old boy who had gastrointestinal, respiratory symptons and septic condition related to milk and soy-based formula. The symptoms appeared within 1-2 hours after every ingestion of milk or soy based formula and intravenous administration of intralipid.