Background: Speech and language delay in children present with delayed milestones and therefore difficulty with expression initially, as well as social skills, reading and writing. The cause of delayed speech is difficult to determine in many cases. Objective: to study the role of allergy that would influence the speech delay in children. Methodology: This study was conducted at the Pediatrics Department in Suez Canal University Hospital, Faculty of Medicine, Ismailia, Egypt from June 2016 to March 2019 on 52 children from both genders suffering from delayed speech. Sublingual immunotherapy was given for all patients for 5 months. Skin Prick test, serum Immunoglobulin E and speech assessment were performed before and after treatment. Results: There was a significant improvement in the number of words children used as well as the number of phrases they produced. Conclusion: There is a relationship between allergic inflammation and delayed speech.