The invention relates to a method and device for measuring blood gas parameters, preferably pH, pCO.sub.2, and pO.sub.2, in a blood sample, where the blood sample of a patient is fed into at least one measuring cell of an analyzer. In order to obtain accurate values for the blood gas parameters even in cases where the temperature of the patient deviates from normal temperature, the temperature of the patient or blood sample is measured upon sample withdrawal, and the measured temperature is transmitted to the analyzer or is recorded by the analyzer, and the temperature of the measuring cell of the analyzer is adjusted to the measured temperature by cooling or heating.