SUMMARY
The article refers to the karyotype analysis of 27 unilateral or bilateral retinoblastoma patients from both sexes, sporadic or familial, before sistemic chemotherapy or at least 6 months after it, selected at A.C. Camargo Hospital/Antonio Prudente Foundation - São Paulo. Patients with congenital malformations, phenotypic alterations or mental retar dation were the priority for this examination. Inespecific chromoso mopathy was founded in 2 patients who were exposed to multiple che motherapy. In other 3 known alte rations were seem (47,XX+G; 46,XY/47,XY+G; 46,XY/46XY, 13q-). The authors discussed these asso ciations and the indications of karyotype analysis in retinoblastoma patients.