A retrospective comparison of urinary excretion of norepinephrine, epinephrine, dopamine and/or their acidic metabolites, HVA and VMA, in 36 children with neuroblastoma versus 360 hospitalized children without neuroblastoma showed a sensibility of 72% and a specificity of 98% for HVA and 80% and 97% for VMA respectively. Consequently, the sensibilities and specificities of these 2 determinations confirm their useful purpose for the biochemical diagnosis of neuroblastoma in preference to the determinations of norepinephrine, epinephrine and dopamine.