Epidermal growth factor receptor (EGFR) gene mutations determine the treatment and prognosis in lung adenocarcinoma. Exon 19 and exon 21 (L858R) deletions represent the most common recognised mutations detected. To date, no figures regarding the prevalence of EGFR mutations in the Irish population have been published. The prevalence of EGFR mutations was retrospectively analysed for all patient samples tested since the introduction of EGFR testing routinely (Mar to Dec 2012) in a single Irish institute. The presence of 41 known treatment linked EGFR mutations in exons 18, 19, 20 and 21 of the EGFR gene was tested in 209 Irish patients. Resection, core biopsy or FNA samples were analysed using a commercially available CE-IVD marked multiplex real-time PCR assay. Samples were included from patients of curative and palliative treatment intent likely to harbour an EGFR mutation.