Background Although bariatric surgeries have proved their safety and effectiveness, they have many adverse effects and complications such as increasing the risk of cholelithiasis. Previous reports measured the incidence of cholelithiasis after bariatric surgeries, but further studies are needed. The present study was designed for identifying the rate of occurrence of cholelithiasis after performance of bariatric surgeries in morbidly obese patients and exploring risk factors for postsurgical occurrence of cholelithiasis. Patients and methods We included 160 patients who underwent bariatric surgeries and followed them from the first day of surgery to at least 1 year. Ultrasound results of patients were collected. We assessed the primary outcome of our study, which was detection of the incidence of occurrence of de novo cholelithiasis in the first year following the bariatric surgeries. We also assessed the secondary outcome of our study, which was determining preoperative risk factors for development of cholelithiasis. Results Of the included 160 patients, 13.75% (n=22) developed postoperative cholelithiasis. The majority (90%) of the patients were asymptomatic. Incidence of cholelithiasis was higher in patients who underwent laparoscopic sleeve gastrectomy more that patients who underwent single anastomosis sleeve ileal or laparoscopic mini-gastric bypass (P=0.049). We found significant associations between cholelithiasis occurrence and patients age (P=0.0.037), smoking, duration of follow-up, percent decrease in weight at 6 and 12 months (P<0.001), diabetes (P=0.011), hypertension (P=0.039), dyslipidemia (P=0.027), obstructive sleep apnea (P=0.034), preoperative weight (P=0.023), and type of performed surgery (P=0.012). Conclusions The incidence of cholelithiasis after preforming bariatric surgery was higher in laparoscopic sleeve gastrectomy more than other procedures, older age of the patients, and high BMI of more than 40 kg/m2.