Background: Diabetes and pre-diabetes are significant risk factors for acute coronary syndrome (ACS) and acute primary stroke (APS). Dysglycemia in any context is under-diagnosed or identified late in resource-poor countries such as in sub-Saharan Africa (SSA), especially when the patient is not known to have pre-morbid diabetes. Materials and methods: We conducted a prospective cross-sectional study at the Aga Khan University Hospital, Nairobi. Inclusion criteria: consenting adults ≥ 18 years admitted with ACS/APS during the period April 2021- February 2022 inclusive. HbA1C was used to determine the glycemic status. Definition of diabetes and pre-diabetes was based on the American Diabetes Association guidelines. Results: From a total of 211 patients [144 (81.2%) of African race], the median age of the patients was 58 (49–68) years with a male to female ratio of 2.5:1. 47.4% (n = 100) had ACS and 52.6% (n = 111) had APS. The prevalence of dysglycemia was 68.2% (95% CI: 61.5%-74.5%) with the prevalence of pre-diabetes being 30.3% (64/211) and type 2 diabetes 37.9% (80/211). Of the patients with dysglycemia, 47.9% (69/144) had a new diagnosis. The average duration of diabetes in patients known to have the condition was 6 years, with a median HbA1C of 8.55 (inter-quartile range 7.21–10.47). 69.4% (137/211) had hypertension as a comorbidity. Among the patients with dysglycemia 73% (101/144) also had hypertension. In the multivariate analysis, age OR 1.05 (1.02–1.08) 95% CI p-value 0.003 and triglyceride levels OR 2.44 (1.44–4.48) 95% CI p-value 0.002 were significantly associated with dysglycemia. Conclusion: This study shows a remarkably high prevalence of dysglycaemia in patients with ACS/APS. The new diagnosis of pre-diabetes prevalence was comparable to diabetes in these patients, adding to the evidence that prediabetes portends significant cardiometabolic consequences and effects over and above the development of type 2 diabetes.