The aim of this study was to evaluate the correlation between I-131 meta-iodobenzylguanidine scintigraphy, urinary vanillylmandelic acid levels and Tc-99m methylene diphosphonic acid bone scintigraphy in the diagnosis of neuroblastoma. We assessed the results of I-131 meta-iodobenzylguanidine used for differential diagnosis and follow-up of 16 children with solid tumors. I-131 meta-iodobenzylguanidine was used for differential diagnosis in 15 patients, for re-evaluation following the treatment in four and for evaluation of the treatment in one patient. I-131 meta-iodobenzylguanidine scintigraphy yielded pathologic findings in all patients with neuroblastoma and was normal in other patients. The sensitivity and specificity of I-131 meta-iodobenzylguanidine scintigraphy was 100% for the diagnosis of neuroblastoma patients. The urinary vanillylmandelic acid levels were high in only two of the 10 patients with neuroblastoma. Tc-99m methylene diphosphonic acid bone scintigraphy was performed in 13 patients with solid tumor and found to be pathologic in 8 patients with neuroblastoma.