A laryngeal cleft is a rare anatomical deformity which is increasingly treated with injection laryngoplasty. Since diagnosis of laryngeal cleft type I is often made between 2 and 5 years of age, this treatment is rarely performed on very young children. In this case, we describe how injection laryngoplasty is performed safely on an 8-week-old child, and we illustrate its added value for the diagnostic process and for temporary symptom relief.