Introduction Diabetes is a major public health concern worldwide. Low and middle-income countries are the most affected. Diabetes self-management can significantly reduce the burden of diabetes complications and mortality. Methods This cross-sectional study was conducted at the outpatient department of a county referral hospital in Kenya, from 1st August 2022 to 30th October 2022. Patients with known type II diabetes of age ≥20 years visiting the hospital for routine follow-up visits were included. A 7-tem Summary of Diabetes Self-care Activities (SDSAC) Questionnaire was used to assess Diabetes self-care activities. For data entry and statistical analysis, SPSS for Windows version 27.0 was used. Results There were 96 (39.2%) males and 149 (60.8%) females. Most of the participants were more than 61 years 148 (60.4%). Prevalence of Diabetes microvascular complications among the study participants was 56.78%, 25.3%, and 14.7% for neuropathy, retinopathy, and nephropathy respectively. significant association was found between the sum scale scores of dietary activities, blood glucose testing, physical activity, foot care, and neuropathy at 95% CI and (P< 0.001). Scores on the Blood glucose testing and foot care activities subscale were significantly associated with Retinopathy (p<0.001). Additionally, significant associations were found between the presence of nephropathy and dietary activities, f00t care, and physical activity subscale (p=<0.oo1). Conclusions Diabetes self-management activities have an impact on microvascular complications in patients with diabetes.