An increase in triglyceride levels in familial hyperlipidemia during pregnancy has been reported. Severe hypertriglyceridemia can lead to complications such as acute pancreatitis, preeclampsia, maternal and fetal complications. Because of the teratogenic effects associated with fibrate therapy in pregnancy, alternative treatment strategies such as insulin as a rapid and potent activator of lipoprotein lipase are required during pregnancy. We report a case of hypertriglyceridemia in a 33-year-old pregnant woman in whom treatment with merely single one time administration of Neutral Protamine Hagedorn insulin was accompanied by a reduction in the serum triglyceride level; to the best of our knowledge, this has never been reported in the literature. Her triglyceride level was 3616 mg/dL before insulin treatment and 1246 mg/dL after insulin treatment. Although this regimen was used safely and effectively in our patient, comprehensive studies are required to evaluate the effectiveness and safety of subcutaneously intermediate-acting Neutral Protamine Hagedorn insulin for the treatment of severe hypertriglyceridemia in non-diabetic pregnant women.