A method of simultaneous analysis of prostaglandins (PGs) and thromboxane (TX) B2 in cerebrospinal fluid (CSF) with GC-MS-SIM was established. Deuterated PGs and TXB2 were used as internal standards: tetra-deuterated PGE2 (d4-PGE2) for PGE2, PGE1 and PGD2; d5-PGF2alpha for PGF2alpha and 9alpha,11beta-PGF2 and 8-epi PGF2alpha; d4-TXB2 for TXB2; and d4-6-keto PGF1alpha for 6-keto PGF1alpha. The PGs and TXB2 were derivatized to the methyl ester of the methoxim dimethyisopropylsilyl (DMiPSi) ether form or the methyl ester of the DMiPSi ether form with simultaneous preparation. Samples were extracted with octadecyl silica gel and purified in two steps with silisic acid gel chromatography between derivatization steps. The calibration curve of each PG and TXB2 was linear from 10 pg to 10 ng with the isotope dilution method. The levels of the seven types of PG and of TXB2 were assayed simultaneously in the cerebrospinal fluid (CSF) from patients with aseptic meningitis. The CSF pattern of the PG and TXB2 concentrations in mumps meningitis differed from those in other types of aseptic meningitis and in disease controls.