Short-term cultures of a fine-needle aspirate from a hepatoblastoma were analyzed cytogenetically. Trisomy 2 was found as the sole abnormality, yielding the karyotype 47,XY, + 2/46,XY. Because trisomy for all or part of chromosome 2 has been described, although together with other aberrations, in seven of the 11 hepatoblastomas hitherto reported, the finding of + 2 as the only anomaly in the present case strongly indicates that additional chromosome 2 material is of pathogenetic significance in this tumor type.