Human genes NY-ESO-1, MAGE-1 and MAGE-3 code for antigens which are expressed in malignancies of various histological types but not in normal tissues except testis. These antigens might therefore represent potential targets for specific immunotherapy. We studied the expression of genes NY-ESO-1, MAGE-1 and MAGE-3 in 98 neuroblastoma tumors by reverse transcription-polymerase chain reaction (RT-PCR). MAGE-1 was expressed in 66%, NY-ESO-1 in 36% and MAGE-3 in 33% of the tumors. NY-ESO-1 gene expression was associated with age older than one year (p = 0.017), more differentiated tumor histology (p = 0.044), elevated urinary vanillylmandelic acid (VMA, p = 0.018) and normal serum ferritin levels (p = 0.023). MAGE-1 expression correlated significantly with normal serum ferritin levels (p = 0.009) and absence of MycN amplification (p = 0.007) while MAGE-3 expression was associated with absence of metastasis (p = 0.027). We conclude that approximately 70% of the neuroblastoma tumors express at least one of the genes coding for NY-ESO-1, MAGE-1 or -3, respectively.