Different congenital and acquired lesions can present as a cystic mass of the neck. The diagnostics and treatment of these is described in this review. Ultrasound and fine-needle aspiration biopsy are essential in the diagnostic workup of neck cysts, and especially cysts located laterally in the neck in adults over 40 years of age require further examination, due to the risk of malignancy. Treatment of the cysts depends on the type and location and can consist of aspiration, surgery, and sclerotherapy. Especially cystic thyroid nodules and macrocystic lymphatic malformations may be treated with schlerotherapy.