Branchial cleft cysts (BCCs) occur due to the incomplete disappearance of the pharyngobranchial ducts during the second to seventh weeks of fetal growth. They are the second most prevalent congenital masses in the head and neck region in children, following thyroglossal duct cysts and sinuses. BCCs are categorized into four types based on their embryological roots. The most common type is the second BCC, accounting for up to 90% of all cases. This type is equally common in both genders and typically manifests in the second to fourth decades of life. They often enlarge and become painful due to infection, usually following an upper respiratory tract infection. A second BCC usually presents as a non-painful, round swelling along the anterior edge of the upper third of the sternocleidomastoid muscle. BCCs are filled with a mucoid, yellow-green fluid containing cholesterol crystals and are typically lined by stratified squamous epithelium overlying lymphoid tissue. The preferred treatment is complete surgical removal of the cyst and tract to prevent recurrence and the need for further intervention. However, if a BCC is infected, it should initially be treated with antibiotics, and if the inflammation does not subside, aspiration or another form of drainage should be considered.