The outcome of laparoscopic sleeve gastrectomy (LSG), one of the most common bariatric surgery (BS) procedure, may differ depending on the patient’s age, gender, preoperative BMI. In this study, we aimed to evaluate the efficacy of LSG technique on weight loss, obesity-associated co-morbidities and complications in patients undergoing LSG over three months and one year, regarding their age, gender, and BMI. The LSG associated complications in participants regarding their preoperative BMI (<39.9 and >39.9), age (30-40 and 40-50), and gender were assessed after 2 3 and 12 months. Besides, the remission and improvement rates of comorbid conditions in patients were examined after 12 months of LSG. Our results showed that LSG led to a significant weight loss in the resolution of obesity-associated co-morbidities and different complications after one year. No significant difference was found in the improvement and the resolution of obesity-associated co-morbidities according to gender. Also, the class 3 patients had significantly higher rates of hearing loss after 12 months and had higher levels of depression and brittle nails three months after the surgery. The younger patients also showed a significantly higher percentage of dry skin, intolerance to bread, and menstrual disorder compared to the older group.