Fanconi’s anemia is characterized by an increased amount of chromosome breaks. The distribution of the breaks in the human karyotype was analyzed in chromosome preparations, stained for G-bands, from lymphocyte cultures of five patients with Fanconi’s anemia. The results showed a remarkable nonrandom distribution of breaks. All the breaks were located at the lightly stained chromosome segments. There was a clear clustering of breaks at some chromosome loci, such as 3q27 and 13q32. Relative lengths of the chromosome regions (Paris Conference, 1971) were measured from karyotypically normal cells, and the distribution of breaks in regions was analyzed statistically. The distal regions of the A-group chromosomes, particularly, showed an excess of breaks, whereas the centromeric areas had fewer breaks. The sex chromosomes had a deficit of breaks.