To explore the clinical characteristics of Wolman disease and diagnostic methods using enzymatic and molecular analysis.Lysosomal acid lipase activity was measured using 4-methylumbelliferyl oleate in the leukocytes of an infant suspected of Wolman disease and LIPA gene mutational analysis was performed by PCR and direct sequencing in the proband and his parents. After the diagnosis was confirmed, the clinical, biochemical, radiological and histopathological findings in this case of Wolman disease were retrospectively reviewed.The sixteen-day-old boy was failing to thrive with progressive vomiting, abdominal distention and hepatosplenomegaly. Abdominal X-ray revealed adrenal calcifications which were confirmed on abdominal CT scan. Xanthomatosis were observed on enlarged liver, spleen and lymph nodes during abdominal surgery. Liver and lymph node biopsy showed foamy histiocytes. The lysosomal acid lipase activity in leukocytes was 3.5 nmol/(mg·h) [control 35.5 - 105.8 nmol/(mg·h)]. Serum chitotriosidase activity was 315.8 nmol/(ml·h) [control 0 - 53 nmol/(ml·h)]. The patient was homozygote for a novel insert mutation allele c.318 ins T, p. Phe106fsX4 in exon 4 on LIPA gene. His both parents were carriers of the mutation.The clinical features of Wolman disease include early onset of vomiting, abdominal distention, growth failure, hepatosplenomegaly and bilateral adrenal calcification after birth. A plain abdominal X-ray film should be taken to check for the typical pattern of adrenal calcification in suspected cases of Wolman disease. The enzymatic and molecular analyses of lysosomal acid lipase can confirm the diagnosis of Wolman disease.