Laparoscopic sleeve gastrectomy (LSG) is one of the most common surgical procedures worldwide for the treatment of morbid obesity. Blake-type drains are widely used in this procedure despite the lack of clear evidence regarding their benefits in the diagnosis and treatment of common postoperative complications such as gastric suture line leak (GSLL) and postoperative bleeding (PB). A retrospective descriptive study with prospective case registry was conducted, analyzing all patients who underwent LSG between January 2012 and December 2022 at a high-volume center. Our primary outcome was to evaluate the role of drains for diagnosis and treatment of GSLL and PB in LSG. Our secondary outcome was to determine drain related surgical site infection (DRSSI) rate. A total of 335 LSG were performed in the studied period. In all patients one abdominal drain was placed during surgery. Six GSLL (1.79%) and 5 PB (1.49%) were recorded. Drain placement did not prove to ensure early diagnosis or conservative management of GSLL or PB after LSG. Furthermore, an incidence of DRSSI of 4.1% (14 patients) was found. In our study, no clear diagnostic or therapeutic benefits of the systematic use of drains for GSLL or PB in LSG was found; but drain use did show a considerable rate of DRSSI, which must be taken into consideration prior to considering drain systematic use. While no randomized prospective trials have been performed, the retrospective data does not support drain systematic use.