In a double-blind, randomized, controlled study, the effectiveness of treatment with a combination of Benfotiamine (an Allithiamine, a lipid-soluble derivative of vitamin B1 with high bioavailability) plus vitamin B6/B12 on objective parameters of neuropathy was studied over a period of 12 weeks on 24 diabetic patients with diabetic polyneuropathy. The results showed a significant improvement (p = 0.006) of nerve conduction velocity in the peroneal nerve and a statistical trend toward improvement of the vibration perception threshold. Long-term observation of 9 patients with verum over a period of 9 months support the results. Therapy-specific adverse effects were not seen. The results of this double-blind investigation, of the long-term observation and of the reports in the literature support the contention that the neurotropic benfotiamine-vitamin B combination represents a starting point in the treatment of diabetic polyneuropathy.