A case is presented of falsely low serum bicarbonate levels with normal arterial blood gas bicarbonate levels in a patient with high triglyceride (TG) levels. This false phenomenon is explained by the presence of high triglyceride levels. Most laboratories use an enzymatic/photometric or indirect ion-selective electrode method to measure bicarbonate. Hyperlipidemia interferes with photometric analysis due to its light scattering effect. An ABG analyser employs a direct ion-selective electrode method that is free from the errors of a photometric analyser. Currently, several methods are available to eliminate the interference of lipemia and allow accurate measurement of biological quantities. The clinical laboratory must establish a protocol for handling lipemic samples according to the biological quantity to be tested.