Periodic endoscopic follow-up is recommended after the diagnosis of Barrett's oesophagus, particularly in patients with dysplasia. The new endoscopic techniques show promising results in identifying areas suspected of housing high grade dysplasia and adenocarcinoma. Endoscopic resection of the mucosa has become a fundamental technique for the complete histological assessment of these lesions and is able to establish appropriate therapeutic decisions. Likewise, this technique may be the therapeutic option in patients with high grade dysplasia and adenocarcinoma, although its application must be complemented with ablation techniques such as radiofrequency to eliminate the residual Barrett's metaplasia. Oesophagectomy associated with lymphadenectomy is the option of choice in patients with submucosal adenocarcinoma. The diagnosis and treatment of patients with early onset high grade dysplasia and adenocarcinoma must be carried out with multidisciplinary teams who can evaluate each case individually. This strategy will enable the oesophagus to be preserved in many patients with high grade dysplasia and indicate oesophagectomy in selected cases.