RELATO DOS CASOS:Foram relatados os casos de três pacientes, dois do sexo feminino e um do sexo masculino, submetidos à cirurgia bariátrica (método restritivo -bypass gástrico em Y-deRoux) que evoluíram, no pós-operatório, com quadro de neuropatia periférica cujo sintoma inicial foi dor neuropática, com posterior ou concomitante envolvimento motor. As eletroneuromiografias demonstraram, nos três casos, uma polineuropatia periférica sensitivo-motora de padrão axonal. Em dois pacientes houve comprometimento intenso dos nervos fibulares. Todos tiveram em comum, antes da manifestação dos sintomas neurológicos, importante perda ponderal num curto período de tempo. CONCLUSÕES:As complicações neurológicas são uma das mais temíveis complicações da cirurgia bariátrica. Nenhum outro fator é mais importante na sua patogenia do que as deficiências nutricionais decorrentes da cirurgia. A vigilância nutricional, evitando-se perdas ponderais acentuadas e rápidas, e a reposição de suplementos são fundamentais para evitar as complicações, sobretudo os quadros neurológicos.Unitermos: CIRURGIA: bariátrica; COMPLICAÇÕES: neuropatia periférica; DOR: neuropática. SUMMARYMenezes MS, Harada KO, Alvarez G -Painful Peripheral Polyneuropathy after Bariatric Surgery. Case Reports. BACKGROUND AND OBJECTIVES:The number of patients undergoing bariatric surgery increases every year, and the frequency of complications associated with this procedure has been increasing. The main complications reported are nutritional, metabolic, neurological, and psychological/psychiatric. Among the neurological complications, peripheral neuropathies are important due to their high incidence. The objective of this report was to stress the importance of this type of complication, in which the initial manifestation might be neuropathic pain followed or accompanied by motor involvement, and whose prognosis depends on early diagnosis and treatment. CASE REPORTS:The case of three patients were reported, two females and one male, who underwent bariatric surgery (restrictive method -Roux-en-Y gastric bypass) and developed, postoperatively, peripheral neuropathy with neuropathic pain as the initial symptom, with posterior or concomitant motor involvement. Electroneuromyography demonstrated in all three cases a sensitive-motor axonal peripheral neuropathy. In two patients, the fibular nerves were severely affected. In common, they all had an important weight loss in a short period of time before developing neurological symptoms. CONCLUSIONS:Neurological complications are one of the most feared complications of bariatric surgeries. Nutritional deficiencies secondary to the surgery are the most important factors in its pathogeny. Nutritional surveillance, avoidance of severe and fast weight loss, and nutritional supplements are fundamental to avoid complications, especially neurological complications.