Delphinidin is an anthocyanidin which is found in fruits and vegetables as a primary plant pigment used for various purposes. The purpose of this study was to investigate the in vitro genotoxic and antigenotoxic effects of delphinidin chloride (DC) in human peripheral blood lymphocytes. Final concentrations of 25 mu M, 50 mu M, 75 mu M and 100 mu M of DC were tested for 24 or 48 hours treatment periods. For detection of possible antigenotoxic potential of DC, human peripheral lymphocytes were co-treated with DC and a known clastogenic agent mitomycin-C (MMC). Genotoxic and antigenotoxic effects of DC were determined with the chromosome aberration (CA) and micronucleus (MN) tests. Cytotoxic effect of DC was determined by measuring the nuclear division index (NDI) and mitotic index (MI). Additionally, total oxidant and antioxidant values were determined by a spectrophotometric method. CA variations resulting from DC treatments did not reveal statistical significance as compared with controls. In tubes treated with DC and MMC together, DC significantly decreased the CA frequency caused by MMC (P <= 0.01). This decrease was almost 50% as compared to the positive control MMC. In this study, DC alone did not lead to the CA and MN formation in all culture tubes. DC did not cause a significant oxidative stress. DC has an antigenotoxic effect against the mutagenic effects of MMC.