We report on three patients (two men with recently discovered type 1 diabetes and one woman with type 2 diabetes and secondary failure of oral antidiabetic drugs) who developed acute painful neuropathy after the institution of effective insulintherapy and rapid drop of glycemia. The EMG disclosed in them traits of mixed lesions of motor-sensory neurons at the level of nerve fibres, more evident in sensory nerves of low extremities. In one patient (A) observed for 5 years, in spite of progressive partial remission of clinical symptoms and signs, no improvement in successive EMG was found. The evident therapeutic effect of alpha-lipoic acid in the presented cases needs to be confirmed in appropriate prospective studies.