Early diagnosis and control of diabetes can reduce premature mortality and disability. We described the diabetes prevalence, awareness, treatment, and control in Mexico City. Data came from the Mexico City Representative Diabetes Survey, conducted between May to June 2015. Participants (20–69 y, n = 1307) reported their diabetes condition, treatment, and outcomes. Fasting blood samples were collected and HbA1c, blood glucose, and blood lipids were determined. We used multivariate logistic regression to identify inequalities in diabetes prevalence and awareness. The overall prevalence of diabetes was 13.6% (95% CI: 11.7, 15.7). Of those living with diabetes, 70.5% were aware of their condition. Among those aware of their diabetes, around 10% to 65% received diabetes care according to international guidelines, and around 30% to 40% achieved HbA1c, LDL cholesterol, or blood pressure targets. Overall, only 4.1% of those aware of their diabetes achieved all treatment targets and 35.4% had never presented a diabetes complication. Diabetes prevalence was higher among older age groups and lower among the most educated. Having access to health care was associated with lower odds for diabetes and diabetes awareness. The low rates of diabetes awareness, treatment, and control highlight the urgent need of strengthening diabetes care in Mexico City.