A rapid, accurate and sensitive UV derivative method was described for measuring the Propofol concentration in some biological fluids. Furthermore two alternative procedures, a gaschromatographic and a colorimetric, were also defined, and the results of the three methods, when applied on blood samples spiked with known amounts of analyte, were compared. The samples were preliminary purified by a solid phase extraction on octadecyl C18 cartridge. The UV derivative method was applied to a pharmacokinetic study on pregnant women undergoing cesarean sections. After an induction dose administration of 2.5 mg kg-1, the maternal and umbilical vein blood were found to have comparable concentrations of propofol, with a mean half like of about 3.5 min; on the contrary no detectable levels of the drug were found in amniotic fluid. The drug recoveries > 98% and the response was linear over the range 0.05-40 micrograms ml-1.