In the past decade, laparoscopic Heller myotomy has emerged as the primary treatment of choice for patients with esophageal achalasia. However, some patients are still referred for surgery only after an unsuccessful endoscopic treatment with dilations or Botulinum toxin (BT) injections. This may result in a more difficult operation with a higher risk of mucosal perforation, and eventually affect the final results of the surgical treatment. In this study we evaluated the effects of a previous endoscopic treatment on the final outcome of surgery in 225 patients who underwent laparoscopic Heller-Dor operation for achalasia from 1992 to June 2004. They were 121 male, 104 female; their median age was 42 years (range 11-80). All the operations were performed by 4 staff surgeons. The majority of the patients (181) underwent surgery without any previous treatment (Group A), whereas 18 had 1 to 4 pneumatic dilations (Group B) and 26 had BT treatment (alone in 22, associated to dilations in 4) (Group C). No differences in the frequency of intraoperative mucosal lesions were detected among the 3 groups (5/181 mucosal lesions in group A, 0/18 in group B and 1/26 in group C, p=n.s.) nor in the median duration of the operation (152 +-34 min, 148 +- 31 min, 139 +- 29 min for group A, B & C, respectively, p=n.s.), even if a subjective impression of a more difficult operation was experienced by all the surgeons in patients of group B and C. None of the patients was lost to follow up. Six patients died for unrelated causes 18 to 69 months after the operation. Median follow-up was 44 months (range 1-131). The 5-year actuarial control of dysphagia showed no differences between patients of group A and B (88% and 92%, respectively); however, only 70% of patients of group C were free of symptoms at 5 years. This finding was even more evident if patients who received BT and dilations were considered separately (50% of dysphagia-free patients at 5 years, p<0.05). Further, a previous treatment with BT significantly correlated with a poor outcome after surgery at logistic regression analysis.