Bariatric surgery is one of the most effective treatments currently available for obesity and its derived comorbidities. However, complications may occur, especially when malabsorptive surgeries like a biliopancreatic diversion is performed. We present the case of a female patient whose obesity was treated with this technique, and in the 9th year of follow-up developed an extensive dermatitis secondary to zinc deficiency and malnutrition, precipitated by therapeutic non-compliance. A close surveillance of early symptoms and signs of nutritional deficiencies as well as chronic supplementation of vitamins and trace elements is required; this case illustrates the relevance of periodical, lifelong visits to a medical physician with special training and experience in the management of post bariatric surgery patients in order to prevent, diagnosis and early treat related complications.