Diabetes mellitus (DM) is a common condition, affecting an estimated 15.5 million people in Africa. Importantly, the prevalence of DM across the continent is expected to double by 2045. [1] Since 2015, this condition has been ranked as the second most common cause of natural death in South Africa (SA), and its impact on healthcare provision is substantial. [2] Accurate assessment of prevalence is difficult owing to the high burden of undiagnosed DM (estimated at 69% in Africa) and the lack of large population studies. [1] In SA, the prevalence of DM is estimated to be between 5.4% and 9.2%. [1,3] There are limited data reporting the prevalence of DM in Western Cape Province, SA, and information with regard to elective surgical patients is minimal. Many studies have shown that DM, especially if poorly controlled, is associated with an increased risk of perioperative complications and mortality. [4-9] In SA, insulin-dependent surgical patients are twice as likely as non-diabetics to die in hospital. [10] Objectives The primary objective of this study was to establish the prevalence of DM in patients presenting for elective surgery over a 1-week period in six Western Cape hospitals. This included patients with a previous diagnosis of DM, and those with a new diagnosis based on screening capillary blood glucose (CBG) testing and a confirmatory elevated glycated haemoglobin (HbA1c) level. The secondary objectives were to assess: (i) the glycaemic control of known diabetics presenting for This open-access article is distributed under Creative Commons licence CC-BY-NC 4.0.