Objectives: To determine if pregnancy-induced hypertension (PIH) is associated with a narrow anion gap. Methods: Chart review of women with uncomplicated pregnancies and those with PIH and varying degrees of proteinuria. Electrolytes, total protein, albumin, creatinine, uric acid, a qualitative or quantitative measurement of urine protein were required for inclusion into the study. Results: A low anion gap relative to women with normal pregnancies was found only in the group of PIH patients who had the greatest degree of proteinuria. The anion gap correlated directly with the concentration of plasma albumin. Women with PIH, proteinuria, and elevated liver transaminases had the lowest plasma albumin values and the smallest anion gap, Conclusion. The degree of hypoalbuminemia determines the magnitude of the anion gap in women with PIH and proteinuria.