The diagnosis of benign hepatic tumor lesions is every day more frequent. Three cases of focal nodular hyperplasia (FNH) accidently detected during the performance of echography and/or CAT for other reasons are presented. The difficulty or diagnostic doubts which the different imaging techniques may present before these findings, together with the relatively young age of these patients may lead to the adoption of a surgical attitude in lesions of a clearly benign character. The role of magnetic resonance (MR) as a non invasive diagnostic technique in this type of disease is of note.