Bariatric surgery is a safe and most effective method of achieving substantial long-term weight loss. Surgery should be considered in case of all patients with a BMI of more than 40 kg/m2 and for those with a BMI of over 35 kg/m2 with obesity-related co-morbidities, after conventional treatment failure. The most frequently used procedures in surgical treatment of obesity performed mostly laparoscopically are restrictive operations limiting energy intake by reducing gastric capacity (vertical banded gastroplasty adjustable gastric band, sleeve gastrectomy) and restrictive/ malabsorptive surgeries also inducing decreased absorption of nutrients by shortening the functional length of the small intestine (Roux-en-Y gastric bypass). Frequent complications following surgery may include hyperemesis, intragastric band migration, gastric perforation, nutritional deficiencies, anastomotic leak, bleeding, anastomotic stricture, internal hernia, wound infection. It is generally recommended for women after bariatric surgery to wait approximately at least 12 months before becoming pregnant. There exists considerable threat that rapid weight loss (relative starvation phase) may be unhealthy for a mother and a baby. Pregnancy after weight loss surgery is not only safe for the mother and the baby but may also be less risky than pregnancy in morbidly obese patients. Postoperative nutrient supplementation and close supervision before, during, and after pregnancy adjusted to individual requirements of a woman can help to prevent nutrition-related complications such as deficiencies in iron, vitamin A, vitamin B12, vitamin K, folate and calcium, and improve maternal and fetal health.