Homologous recombination is a DNA double-strand break (DSB) repair mechanism that usually uses homologous DNA as template. Keskin et al. now report that Saccharomyces cerevisiae uses mRNAs as template for homologous recombination. The authors designed a system to monitor DSB repair through the restoration of a prototrophic marker (His+) by homologous mRNAs. In cells deficient in reverse transcription, deleting the genes encoding the RNases H1 and H2, which cleave RNA hybridized to DNA and thus could potentially inhibit RNA reccombination with DNA, resulted in a marked increase in His+ colonies with precisely repaired loci. Successful repair required also transcription and splicing. The data demonstrate that mRNAs can be templates for homologous recombination in yeast. This mechanism could be important, for example, in non-dividing cells, which lack sister chromatids, or in individuals in which RNA–DNA heteroduplexes are more stable owing to mutations.