Cyst of Nuck is an infrequent disease originated in the inadequate obliteration of the processus vaginalis during the embrionary life of the woman. Clinically usually appears as a slowly growth inguinal tumor, painless, smooth, soft, fluctuant and irreducible. Differential diagnosis must include inguinal hernia and other etiologies of inguinal tumor, for which echography is the main diagnostic test. Treatment consists on surgical extirpation and local reparation. It is exposed a case of a patient with cyst of Nuck clinically typical.It is made a review of clinical, diagnostic and therapeutic approach of this disease.