Barrett's oesophagus (BO) is the primary precursor lesion for oesophageal adenocarcinoma (ADC). The natural history of metaplasia-dysplasia-carcinoma sequence remains largely unknown. HER2/neu oncogene results overexpressed/amplified in preneoplastic lesions and in ADC of the oesophagus and it has been associated with poor prognosis. Our aim was to evaluate the role of HER2 overexpression/amplification in predicting the conversion from precursor lesions to ADC. We retrospectively evaluated by univariate analysis of single variables clinical records and histological specimens of 21 patients with a confirmed diagnosis of BO and/or oesophageal dysplasia. Clinical variables included age, gender, alcohol and smoking intake, presence of symptoms (pyrosis, disphagia) and endoscopic features (length). HER2 status was studied by immunohistochemistry and fluorescence in situ hybridization (FISH) on paraffin-embedded tissue. The end-points were the occurrence of progression and the time-to-progression (TTP) from the initial histologic lesion to the worst pathological pattern. Median age at diagnosis was 63 years (range 37-84). BO median length was 4.5 cm. Progression occurred in 11 of 21 patients and median TTP was 24 months. HER2 was overexpressed/amplified in 8 of 21 (38%) patients. HER2 overexpression/ amplification and the presence of dysplasia were statistically associated with progression (P= 0.038). This study provides evidence for a possible role of HER2 in the transition from dysplasia to ADC of the oesophagus. This fact could help in identifying patients at high risk of malignant transformation.