Bariatric surgery is a treatment that guarantees a substantial and lasting weight loss in addition to thetangible benefits relating to obesity-associated medical conditions. The increasing number of bariatric surgeries has revealed an increasing number of complications related to this procedure, including Wernicke´s encephalopathy and vitamin B deficiency polyneuropathies. Herein, a 7-week post-surgerycase of Wernicke´s encephalopathy is presented that emphasizes the importance of an early recognition of these symptoms so as to initiate intervention during the reversible phase of these potentially lethal pathologies. doi: http://dx.doi.org/10.7705/biomedica.v32i4.765