A gas chromatographic method is reported for the quantitation of the antibiotic spectinomycin hydrochloride in bulk drug or sterile suspension formulation. The method, having a relative standard deviation of approximately one percent, involves silylation of spectinomycin to a tetrakis trimethylsilyl derivative from which a single gas chromatographic peak is obtained. Mass spectral data employed to determine the number and positions of the trimethylsilyl groups on the derivatized spectinomycin molecule are discussed.