Background: Diabetes mellitus is a diverse group of metabolic disorders initiated by either a lack of insulin, resistance to its effects, or both. The oral cavity and its associated structures are also affected by the local and systemic effects of this condition. The aim of this study was thus to determine the oral health awareness and oral self-care practices of a group of patients registered for care at the diabetic clinic of the Lagos State University Teaching Hospital, Ikeja, Lagos State (Lasuth). Methods: This descriptive cross-sectional study was conducted at Lasuth. The study included 120 respondents. A structure interviewer administered questionnaire was used to assess the social background, medical history, utilization of dental services and the knowledge, values and attitude of the respondents towards oral health. Results: Pain or emergency treatment 64 (53.3%) was the main reason for dental attendance and the primary reason for not attending the dental clinic was perceived lack of need for dental care (22; 18.3%). Xerostomia or dry mouth (89; 74.2%) was the commonest dental complaints by the participants. There was a significant association between the age (p=0.000); educational qualification (p= 0.000); smoking status (p=0.000); duration of diabetes (p=0.000); diabetes type (p=0.000); blood sugar control (p=0.000); and the amount of oral health information received (p=0.000); with the number of dental complications experienced by the participants. Conclusion: This study revealed that the oral self-care behaviour of patients with diabetes was not consistent with their increased risk for oral diseases. Our findings suggest that there is a significant need for increased knowledge of the oral complications of diabetes mellitus and the adoption of preventive oral hygiene behaviours that would improve their oral health.