Purpose: To determine whether pre-surgical treatment using long-acting somatostatin analogues (SSAs) may improve surgical outcomes in acromegaly. Methods: Retrospective study of 48 patients with acromegaly operated by endoscopic transsphenoidal approach and for first time. Surgical remission was evaluated based on the 2010 criteria. Results: Most patients, 83.3% (n=40), harboured macroadenomas and 31.3% (n=15) invasive pitu-itary adenomas. Fourteen patients were treated with lanreotide LAR and 6 with octreotide LAR, median monthly doses of 97.5 [range 60-120] and 20 [range 20-30] mg, respectively, for at least 3 months preoperatively. Presurgical variables were comparable between pre-treated and un-treatred patients (P>0.05). Surgical remission was more frequent in those pre-treated with monthly doses ≥90 mg of lanre-otide or ≥30 mg of octreotide than in untreated or pre-treated with lower doses (OR=4.64, P=0.025). However, no differences were found between pre-treated and untreated patients when lower doses were included or between those treated for longer than 6 months compared to those untreated or pre-treated for shorter than 6 months. Similarly, no differences were found either in terms of surgical or endocrine complications (OR=0.65, P=0.570)), independently of the doses and the duration of SSA treatment (P>0.05). Conclusions: The dose of SSAs is a key factor during pre-surgical treatment, since the beneficial effects in surgical remission were observed with monthly doses equal or higher than 90 mg of lanreotide and 30 mg of octreotide, but not with lower doses.