One hundred sixty-seven women with secondary amenorrhea were observed from six months to four years. In 66 patients, the amenorrhea followed the discontinuation of oral contraceptives (postpill) while in the remaining 101 the amenorrhea was not temporally pill related (non-postpill). Galactorrhea was present in 43 (65%) of those with postpill amenorrhea and in 32 (32%) of those with non-postpill amenorrhea (p less than 0.001). Tomography of the sella turcica was performed in the 75 women with galactorrhea and in the 35 without galactorrhea who did not have withdrawal uterine bleeding following progesterone administration and who had low or normal serum follicle-stimulating hormone levels (hypothalamic-pituitary failure). Forty of the 75 patients with amenorrhea and galactorrhea had radiographic evidence of a pituitary tumor whereas only eight of 35 patients with hypothalamic-pituitary failure without galactorrhea had an abnormal sella turcica (p less than 0.01). The incidence of radiographic abnormalities in those with galactorrhea was similar in both the postpill and non-postpill groups.