The degree of red coloration (DRC) in pericarp of rice depends on the content of flavonoid compounds which have beneficial health effects for humans. In this study, 182 backcross-recombinant inbred lines (BILs) derived from Koshihikari (white pericarp)/Kasalath (red pericarp)//Koshihikari were used to detect the genomic regions associated with DRC through the QTL mapping approach. As a result, a total of four genomic regions were found to associate with DRC on chromosomes 1, 7, 9 and 11, respectively. Interestingly, the two genomic regions having the largest effects corresponded to previously characterized Rc and Rd genes on chromosome 7 and 1, respectively. In addition, two novel genomic regions having minor effects on DRC and located on chromosomes 9 and 11, respectively, are reported here for the first time. These results and the identification of tightly linked molecular markers that flank the genomic regions provide an opportunity for marker-aided improvement of red coloration in pericarp of rice.