Diabetes mellitus (DM) has emerged as a global public health concern with significant upshots due to its high prevalence, severity and associated complications. The present review aims to evaluate the literature that has investigated the awareness and attitude of diabetic patients about their oral/periodontal health to identify gaps in the dissemination of this critical information. Literature addressing diabetic patient’s awareness/knowledge, response to their periodontal health needs, and the source of oral health education was investigated using a computer search of electronic databases. Twenty-six papers were included in the systematic review for analysis. The studies reported data from 13 different countries involving 10 550 participants, 9843 patients with DM and 974 healthy controls. The overall analysis of the studies showed that approximately 73% of the diabetic patients were unaware of the link between their systemic condition (DM) and periodontal health. The results of the study show that a large number of diabetic patients are unaware of the link between oral/periodontal health and DM. There is a strong need to implement the recent guidelines established by the IDF/EFP concerning mutual care of diabetic patients by the medical and dental health care professionals. This will result in improved general and oral health of our diabetic patients.