Peripheral nerve injuries are difficult to treat, and the clinical outcome after surgical repair and reconstruction is still insufficient, particularly concerning recovery of sensory function. To improve the clinical treatment strategies, experimental models are used to systematically examine the mechanisms behind nerve regeneration and assess the improvement of nerve regeneration by introduction of new surgical nerve repair and reconstruction methods (e.g., novel devices made by bioartificial materials). Rat models, where the sciatic nerve has essentially a similar size as a human digital nerve, are widely used to evaluate nerve regeneration with the inherent advantages and disadvantages of the experimental models. Estimations revealing that a large number of diabetic patients will eventually suffer from peripheral nerve injury have motivated development of suitable experimental diabetes models for studying the nerve regeneration process and novel treatment approaches. We have successfully used the Goto-Kakizaki rat model, which shows moderately increased blood sugar closely resembling type 2 diabetes, for assessing the surgical peripheral nerve regeneration potential with and without artificial scaffolds. In order to improve outcome after repair and reconstruction of nerve injuries, one has to have a clear concept concerning how to evaluate novel repair and reconstruction techniques in experimental models before clinical studies can be initiated in an accurate way.