Background Neutral lipid storage disease with myopathy (NLSDM) has obscure onset and nonspecific clinical symptoms. Due to different clinical manifestations, the patients with NLSDM may be seen in neurology, cardiovascular disease and other departments, which may easily lead to missed diagnosis and misdiagnosis. The definitive diagnosis depends on genetic detection, but most patients delay treatment because they cannot be diagnosed in time. The peripheral blood leukocytes of such patients have typical morphological characteristics, which can prompt clinicians to improve genetic testing in time to confirm the diagnosis. Objective To investigate the morphological characteristics of peripheral blood cells in NLSDM patients. Methods 3 NLSDM patients admitted to Peking University First Hospital from June to August 2021 were selected as the subjects, the peripheral blood of the patients was collected to prepare blood smears, and the morphological characteristics of blood cells were observed by Wright-Giemsa staining, neutrophil alkaline phosphatase (NAP) staining, myeloperoxidase (MPO) staining and periodic acid-schiff reaction (PAS) . Results Wright-Giemsa staining: several circular vacuoles of different sizes can be seen in the cytoplasm of neutrophils, eosinophils, basophils, and monocytes; NAP: the neutrophil cytoplasm of NLSDM patients was negative, which was significantly different from normal and infected patients, the positive rate and integral value of infected patients were significantly increased; MPO: patients with NLSDM were positive which were similar to healthy individual but weaker than infected patients (the large positive particles covered the nucleus, resulting in unclear nuclear structure) . PAS: there was no significant difference in the positive degree of NLSDM patients, healthy individual and infected patients. Conclusion Vacuoles of different sizes can be seen in the cytoplasm of various leukocytes in the peripheral blood of NLSDM patients, while neutrophil vacuoles are different from the toxic changes during infection, which can be preliminarily identified by NAP staining. Such morphological abnormalities are characteristic changes of NLSDM.