Typhlonectes compressicauda is a viviparous gymnophionan in which metamorphosis occurs during gestation. The development of the hypophysis and thyroid gland, both implicated in metamorphosis of other amphibians, has been poorly studied in gymnophionans. In this species, the adenohypophysis blastema, equivalent to Rathke's pouch, appears at stage 23. At stage 24, the anlage extends toward the diencephalon floor, forming a flat lens. At stage 26–27, at or just after hatching, the nerve fibers develop from the diencephalon, constituting the future pars nervosa. At the beginning of metamorphosis (stages 30–31), the differentiation of five endocrine cell types, resembling those of adult animals, is observed, suggesting the beginning of endocrine activity. The development of the thyroid gland from the pharyngeal endoderm, equivalent to the thyreoglosse canal, is first observed at stage 22. At stage 24, the anlage is divided into two lobes extending to the sinus venosus. At stages 26–27, a central lumen appears in the follicles. At stage 28, the morphology of the thyroid gland is that of an adult. Colloids fill the follicles at stages 29–30, before the threshold of metamorphosis. These observations suggest the association of development and activity of the thyroid gland with the metamorphic process, as in other Amphibia. A relative independence of thyroid endocrine activity with hypophyseal hormonal control (and consequently hypothalamus control) is suggested as in aquatic urodeles, at least at the beginning of metamorphosis.