Pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) is an effective treatment for chemotherapy-induced neutropenia. However, it can also induce various adverse effects, including fever, bone pain, and other discomforts arising from the abnormal proliferation of blood cells. This study presents an analysis of a case involving a middle-aged patient with small cell lung cancer who exhibited transiently low blood glucose levels without experiencing any symptoms of hypoglycemia following PEG-rhG-CSF treatment. After thorough evaluation by clinicians and pharmacists, the condition was diagnosed as pseudohyperglycemia, a phenomenon distinct from true hyperglycemia. The article provides a pharmaceutical perspective on the contributing factors, mechanisms, and management strategies for pseudohypoglycemia, offering valuable insights for clinical practice.© 2024 The Author(s).