Aim: To investigate the level of diabetes knowledge in a population with type 2 diabetes (T2D) and a high prevalence of illiteracy, to identify the main gaps in the knowledge and to study the determinants of the knowledge score., Methods: This cross-sectional survey involved 24 diabetes clinics and Kuwaiti adults with T2D (n=5114), and used the Michigan Diabetes Knowledge Test., Results: The participants' mean age (+/-S.D.) was 55.6+/-10.4 years; 68.2% were women, 45.0% were illiterate, 52.2% reported a family income equivalent to 1200 to 2400 euros per month and only 28.6% performed glucose monitoring. Mean+/-S.D. HbA(1c) was 8.76+/-2.3%. Their mean score for the total knowledge test was 58.9%. Knowledge deficits were apparent in the questions related to diet and self-care. Participants who were older, and with lower educational levels, limited family income, negative family history of diabetes or were smokers had significantly lower knowledge scores. The scores were also lower in those who had shorter disease duration and fewer complications, were taking insulin, had less frequent insulin injections, performed less glucose monitoring and had lower HbA(1c) levels. Education, family income, glucose monitoring and presence of complications were independent determinants of the knowledge score., Conclusion: Knowledge of diabetes in a T2D population with a high prevalence of illiteracy was poor. Limited family income and lack of self-care are other predictors of knowledge deficits. Efforts need to be focused on educational programmes with strategies to assist T2D patients of limited education and income to manage their disease more effectively.