The addition of 0.1% caffeine to the plating medium markedly reduced the ozone-survival of the wild-type and the rad1 and rad6 mutants of Saccharomyces cerevisiae, whereas no effect was observed in the rad52 mutant. Since, in S. cerevisiae, caffeine has been reported to interfere with the recombinational repair pathway under the control of the RAD52 gene, these results support previous observations suggesting that this pathway is involved in the repair of ozone-induced DNA damage.