An extraction replication technique to study foreign particles with tissues was reported. Sections of tissue were immersed in xylene and ethanol and the dehydrated tissue then embedded to a thin sheet of acetone softened cellulose-acetate mounted on a glass slide and allowed to harden. The slide was removed, leaving the embedded tissue in the cellulose-acetate. A shallow well on the tissue was outlined with Scotch tape and a 10 percent by volume solution of polyvinyl-alcohol (PVA) was applied. The hardened PVA was stripped from the section, providing a replica of the tissue surface. Any foreign particles present in the tissue were removed and successive strippings were made when necessary. The surface replicas were then preshadowed with platinum, covered with a carbon film for strength, and the PVA removed by floating the replicas in a hot water bath. These were examined by electron microscope. No asbestos particles were found in any of the tissues. Talc (14807966) particles identifiable as the characteristic decoration pattern induced by the evaporation of platinum in vacuo on the crystal surface were found in 10 of 13 (75 percent) ovarian tumors. The talc particles (1000 Angstroms to 2 microns in size) were found deep within the tumor tissue. Talc crystals as large as 5 microns were found embedded within tumors of the cervix in 12 of 21 (50 percent) cervical tumors. Numerous talc particles were found in the primary endometrial carcinoma of one tissue sample but none in the metastatic ovarian tumors. Talc particles were also observed in 5 of 12 normal ovarian tissues. Preliminary evidence that the crystals contained magnesium (7439954) and silicon (7440213), was obtained by electron microscopic microanalysis. The authors suggest that although it is impossible to incriminate talc as the primary cause of carcinomatous changes in the cervix or ovary on preliminary observation, the possibility that talc may be related to other predisposing factors should not be disregarded.