A 43-year-old woman was admitted to our hospital due to type 2 diabetes, dyslipidemia, and hypertension. Her triglyceride levels remained around 300-500 mg/dl with oral administration of pemafibrate and omega-3-acid ethyl esters granular capsules. Her diabetes and dyslipidemia had worsened since winter 2023, and at the time of her regular visit in February 2024, her triglyceride level had worsened to 4926 mg/dl. She developed epigastric pain at noon on the day after her regular outpatient visit. Although she was treated with over-the-counter medication for 1 day, there was no improvement and she was referred to our hospital. A computed tomography scan revealed swelling of the pancreatic head and fluid collection up to the right side of the perirectal space, and she was diagnosed with severe acute pancreatitis. Her triglyceride level decreased and her clinical symptoms improved with large-dose fluid replacement, meropenem injection, ulinastatin infusion, and continuous intravenous insulin and heparin infusion. In this case, acute pancreatitis was thought to be induced by worsening diabetic control, which was associated with an increase in triglycerides. Continuous intravenous injection of insulin and heparin was useful for treatment.