The study investigated whether there is a significant association between erectile dysfunction (ED) secondary to autonomic failure, and cardiovascular autonomic neuropathy (CAN) in male patients suffering from type 2 diabetes. Twenty-two patients suffering from type 2 diabetes were recruited for this study after satisfying the stringent exclusion criteria used in the first stage. They had no evidence of overt cardiovascular disease, hypertension, neurological, renal or thyroid disease. Each subject was assessed for ED and CAN using standardized tests. Six patients were suffering from CAN while 10 patients were suffering from ED. There was no significant association between CAN and autonomic ED (P = 1). Three patients with normal erectile function had CAN, whilst three patients with ED had CAN. Further analysis demonstrates a significant increase in association between ED and CAN with age (P = 0.036). These results show that ED secondary to autonomic neuropathy is not significantly associated with CAN in this specific group of patients. Nonetheless, the study reveals that ED is a sentinel symptom for future development of CAN.