Roux-en-Y gastric bypass (RYGB) is a commonly performed procedure in the surgical treatment of morbid obesity. Since a major anatomical alteration is made, this procedure may lead to significant postoperative complications, including nutritional deficiencies related to malabsorption. As a consequence of micronutrient deficiencies, secondary metabolic, hematologic and neurologic complications might also develop. Each of these complications is well reported in the literature; however, there are limited data on the simultaneous occurrence of these complications in a single patient. In this report, we aimed to present the diagnosis and management of metabolic, hematologic, neurologic and cardiac complications, which occurred simultaneously in a 57-year-old female patient after undergoing laparoscopic RYGB procedure.