Fused-silica capillary columns were evaluated for the resolution of oxidized cholesterol derivatives. Thermal instability of diol derivatives, epimeric 7α- and 7β-hydroxy, 4β-hydroxy, and 25-hydroxycholesterol, was observed during gas chromatography. After derivatization as trimethylsilyl ethers the foregoing diols, α-epoxide, cholestane-triol, 7-ketocholesterol, and cholesta-3,5-dien-7-one were completely resolved on a DB-1 column. Each oxidized sterol revealed excellent response linearity as the trimethylsilylated sterol, enabling reliable quantification. The identity of each derivatized sterol was confirmed by mass spectrometry.