Pyrrolidine dithiocarbamate (PDTC) is considered an antioxidant and is frequently used to study the role of free radical reactions in various biological processes and against free radical-induced cellular injuries. However, its antioxidant properties are not characterized. In this study, electron spin resonance (ESR) was used to investigate the antioxidant potential of PDTC with hydroxyl radical (*OH) and superoxide anion radicals (O2*-). The Fenton reaction [Fe(II) + H2O2 --> Fe(II) + *OH + OH-)] and xanthine and xanthine oxidase were used as sources of *OH and O2*- radicals, respectively. The results show that PDTC effectively scavenges *OH radicals with a reaction rate constant of approximately 2.73 x 10(10) M(-1) s(-1), which is comparable to other efficient *OH radical scavengers, such as ascorbate and glutathione. PDTC is also able to scavenge O2*- radicals. Through its antioxidant properties, PDTC protects against Cr(VI)-induced DNA strand breakage.