To ascertain whether the pituitary intermediate lobe is able to produce adrenocorticotropic factorsin vivoinTriturus carnifex, two groups of animals were subjected to ectopic pituitary auto‐graft. Animals of one group were sacrificed two months after the autograft; those of the second group one year after the operation. Immunocytochemical study of ACTH and MSH revealed that, in the autograft, only in the second group was the intermediate lobe immunopositive to an antiserum against synthetic ACTH (anti‐ACTH). This result supports the hypothesis that the pituitary intermediate lobe can produce adrenocorticotropic factorsin vivo.