SUMMARY: The effect of testosterone injections on the histology of the submaxillary salivary glands, and their content of nerve growth factor (NGF), were studied in normal and gonadectomized male and female mice, and in those affected with testicular feminization (due to the X-linked gene, Tfm). In intact and spayed female and castrated male mice testosterone increased the quantity of NGF and caused the histology of the glands to become like the male type. In mice with testicular feminization both the histology and the NGF content were of the female type, and were completely unaffected by testosterone injections. Female mice heterozygous for Tfm responded to testosterone, but in some the response appeared intermediate. The submaxillary gland provides a suitable test organ for studies of the androgen insensitivity of Tfm mice, and may prove more useful than the kidneys for some experiments.