ABSTRACT.- Genome editing success in crop species is largely dependent on the availability of highly efficient plant transformation protocols. Tomato (Solanum lycopersicum) was the first dicotyledonous crop to be successfully mutagenized using CRISPR-Cas9. Despite many efforts, no standardized, simple protocol is available for non-model tomato genotypes. With the increasing availability of gene editing tools, the transformation of elite tomato breeding lines has gained importance because mutant variants can be easily incorporated into breeding programs. This chapter describes a protocol for transforming and gene editing in elite tomato breeding lines, reaching 3.6% transformation efficiency. © The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature 2025.