Delayed puberty is clinically defined as the lack or incomplete development of secondary sexual characteristics by an age when 95% of children of the same sex and culture have begun sexual maturation. The clinical staging of puberty is performed by the criteria established by James Tanner. Delayed puberty usually results from inadequate gonadal steroid secretion, which, in turn, is most often caused by defective gonadotropin secretion from the anterior pituitary due to defective production of gonadotropin-releasing hormone (GnRH) from the hypothalamus, the key functional defect in patients with constitutional delay of puberty. It can, however, also be caused by a variety of hypothalamic, pituitary, and gonadal disorders. This case explores a patient who presents with signs and symptoms of delayed puberty and challenges students to determine the cause.