Oligonucleotide-directed gene repair is a potential technique for agricultural trait modification in economically important crops. However, large variation in the repair frequencies among the scientific reports indicates that there are many factors influencing the repair process. We report here a transient assay system using GFP as a reporter for testing the efficiency of plasmid DNA repair in cultured wheat cells. This assay showed that osmotic medium supplemented with 2,4-D increased the oligo-targeting frequency, and that the repair of a point mutation was more efficient than repair of a single base deletion mutation in cultured scutellum cells of immature wheat embryos. This study provides the first evidence that oligonucleotide-directed mutagenesis is applicable to regenerable cultured wheat scutellum cells.