History and Objectives: Arterial blood gases (ABG) have various clinical diagnostic values, however their normal values are not known in our country. Therefore, this investigation was conducted in order to determine normal values for PaO2, PaCO2, HCO3- and pH among healthy 18-74 years old in autumn and winter of 1995 in Kashan.

Materials and Methods: A descriptive study on 121 randomly selected healthy individuals from medical records. Arterial blood was taken from the radial blood arteries in order to determine the normal values and the confidence intervals.

Results: Normal values of PaO2 were 91.9±9.8 mmHg and 94.4±11.5 mmHg in men and women respectively. The linear formula was PaO2=103.59-0.29 X age (year) and PaCO2 values were 38±3.5 mmHg and 36±4.36 mmHg for men and women respectively. The normal values for HCO3- were 22.6±2.12 meq/L and 21.4±1.96 meq/L for men and women respectively and pH values were 7.4±0.02 and 7.4±0.04 for men and women respectively.

Conclusion: Values for arterial blood gases can have clinical application in Kashan and it is suggested that they may be used in clinical laboratories.