Diabetes can cause diabetic neuropathy, a frequent and crippling consequence that is characterised by damage to the nerves that can cause a variety of motor, sensory, and autonomic symptoms. The proper treatment of diabetic neuropathy requires a timely and accurate diagnosis. Clinical evaluation, neurological examination, patient history, and specialised diagnostic tests such as nerve conduction studies, electromyography, and quantitative sensory evaluations are used to accomplish this. Advanced diagnostic technologies like skin biopsies and imaging techniques have also become essential for confirming the diagnosis and assessing the extent of nerve damage. Nonetheless, there are some neurological disorders, such as vitamin deficiencies, genetic neuropathies, and chronic inflammatory demyelinating polyneuropathy (CIDP), that can mimic the symptoms of diabetic neuropathy. Differential diagnosis is therefore essential for separating diabetic neuropathy from other neuropathy causes and for directing the most effective course of therapy. The diagnostic methods for diabetic neuropathy are discussed in this chapter, along with the significance of a thorough evaluation in order to distinguish it from other disorders. Clinicians must have a deep grasp of these diagnostic techniques in order to deliver focused, efficient treatment that ultimately enhances patient outcomes and quality of life.