Lactation ketoacidosis is an uncommon cause of high anion gap metabolic acidosis affecting breastfeeding women due to increased metabolic demands, reduction in carbohydrate intake, and acute illness. Meanwhile, recent literature showed that COVID-19 might cause ketosis, ketoacidosis, and diabetic ketoacidosis. We report a case of a 22-year-old lady, four weeks postpartum, with a confirmed diagnosis of COVID-19. She presented with severe symptomatic ketoacidosis with a high anion gap, ketonuria and hypoglycemia that was due to lactation ketoacidosis. She was not tolerating orally for days because of abdominal pain, vomiting, and viral infection. After proper treatment in the ward for the presenting symptoms of lactation ketoacidosis and refeeding, she rapidly improved and discharged five days later. While ketoacidosis may be induced by starvation and/or lactation, it is our conclusion that the condition may be aggravated by COVID-19 infection. Emergency services should consider the risk of lactation ketoacidosis exacerbated by COVID- 19 in postpartum women.