Background: In patients under general anesthesia, the laryngeal mask airway (LMA) is a valuable alternative to endotracheal intubation to maintain the airway. In this study, we compared the efficacy of LMA with an endotracheal tube (ETT) in plastic and reconstructive surgeries over 2 h on thorax and abdomen under general anesthesia in Hazrat Fatemeh Hospital in Tehran, Iran, in 2020. Methods: This randomized clinical trial was performed on a sample size of 80, randomly assigned to two groups. The main variables included the ease of placement, recurrent carbon dioxide content, arterial oxygen saturation, and laryngeal and tracheal spasm. In addition, the sub-variables entailed the mean duration of anesthesia, nausea and vomiting, sore throat, and abdominal distension. The obtained data were analyzed by the SPSS software version 25. Results: In the present study, 76 patients were female. Mean age, recurrent carbon dioxide, arterial oxygen saturation, laryngeal and tracheal spasm, the mean duration of anesthesia, nausea and vomiting, sore throat, and abdominal distension were not significantly different between the two groups. Conclusions: The results of this study showed that the classic laryngeal mask could be used as a means of airway control in general anesthesia for long-term surgeries of more than 2 h.