Objectives: Fourth branchial cleft anomalies are rare and often misdiagnosed. They typically present as sinus tracts opening into the pyriform sinus. Diagnosis is traditionally confirmed using barium swallow or rigid laryngoscopy, both of which have limitations. This study highlights the advantages of flexible f iberoptic endoscopy for direct visualization of the tract opening—an essential step for accurate diagnosis— while avoiding radiation exposure and the need for rigid instrumentation. Methods: We retrospectively reviewed seven pediatric cases referred to our tertiary medical center between 2020 and 2024. All children presented with cervical infections and were ultimately diagnosed with fourth branchial cleft sinus. Results: The series included seven children (five boys, two girls), aged 1 to 13 years. All had left-sided sinus tracts. Six children presented with a first episode of neck infection; one had a recurrent episode. In every case, diagnosis was confirmed by direct visualization of the tract opening in the pyriform sinus using flexible fiberoptic endoscopy. All patients were treated with endoscopic diathermy cauterization. One child experienced recurrent infection, suggesting procedural failure. Conclusion: Diagnosis of fourth branchial cleft sinus relies on identifying the internal tract opening. Flexible endoscopy offers a safe, minimally invasive, and radiation-free method for achieving this, with the added benefit of being feasible in awake or lightly sedated children. Further studies are warranted to assess the effectiveness of tract cauterization using flexible endoscopy equipped with a working channel.