Dislcosed is the use of eicosapentaenoic acid in the manufacture of a medicament for treating high triglycerides in a subject receiving statin therapy, wherein the medicament is formulated to provide about 1100 mg, about 1650 mg, or about 2200 mg of the eicosapentaenoic acid and not more than about 20% docosahexaenoic acid, by weight of fatty acids present in the medicament. Another use disclosed is the use of eicosapentaenoic acid in the manufacture of a medicament for lowering triglycerides without increasing LDL-C by more than 20% in a subject having triglycerides of at least 500 mg/dl, wherein the medicament is in one or more dosage units and comprises: an amount of eicosapentaenoic acid selected from the group consisting of: about 1100 mg, about 1650 mg, and about 2200 mg, and not more than about 30%, by weight of total fatty acids, docosahexaenoic acid. Also disclosed are pharmaceutical composition comprising at least 95% EPA enclosed in a capsule shell, wherein the composition has a baseline peroxide value not greater than 5 Meq/kg and upon storage of the composition at 25°C and 60% RH for a period of 6 months, the composition has a second peroxide value not greater than 8 Meq/kg. The compositions are useful in the treatment of cardiovascular-related diseases.