Sodium, potassium, and chloride levels are artifactually depressed in hyperlipemic sera. Accurate electrolyte levels are needed for management of patients with hyperlipemia, but present methods for correcting the values (serum water and/or osmolality determinations) either are technically cumbersome or fail to provide accurate data to correct the falsely low levels. Alternatively, to determine true sodium, potassium, and chloride concentrations in hyperlipemic sera, only the required electrolyte values and the triglycerides are measured. The percentage by which the measured electrolyte levels in the hyperlipemic sample must be increased to approximate the true values is given by the following equation: per cent increase = 2.1 X triglycerides (Gm./dl.) - 0.6.