A sensitive, 1-step sample prepn. method for detection of volatile, low mol. wt. (LMW) cyclic silicones hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in plasma and blood by gas chromatog. coupled with mass spectrometry (GC/MS, SIM mode) is presented. In spiked expts., extn. efficiencies for these siloxanes (100-20 000 ng/mL) were approx. 90% for plasma and approx. 80% for blood; only in the case of D3 was the recovery very low. Plasma and blood of women who are or were exposed to silicone gel-filled implants and of control subjects were analyzed for low mol. wt. silicones. D3-D6 were not detectable in control plasma or blood. Although the investigated nos. of patients samples are very limited, and thus, no statistical anal. is possible, our data clearly show a general increase in the amt. of LMW cyclic siloxanes in the bodies of women with silicone implants. In particular, several years after ruptured silicone implants were removed, siloxanes could still be found in blood samples from several women. The Siloxane compd. D3 varied between 6 and 12 ng/mL (plasma) and between 20 and 28 ng/mL (blood), whereas the concn. range of D4 was 14-50 ng/mL (plasma) and 79-92 ng/mL (blood). D5 and D6, with 1 exception, were not detected.