Tumor tissue, including breast cancer, thyroid carcinoma, uterine sarcoma, renal carcinoma, and granulosal thecal cell ovarian tumor, from twelve different patients, was analyzed for sterol content by thin-layer and gas-liquid chromatography. Cholesterol was present in large amounts in all. A sterol with the retention time of desmosterol was present in 11; one with the retention time of stigmasterol in 3; of which, 2 also contained a sterol with the retention time of campesterol, and 1 of β-sitosterol. Thus, the finding of osteolytic sterols in breast cancer by Gordan and associates is partially confirmed and extended. © 1969.