Literature supports the relationship between increased diabetic knowledge and improved health outcomes among individuals with Type II diabetes mellitus (T2DM). In Kenya, knowledge gaps within the at-risk population still exist about the symptoms, complications, and management strategies of T2DM, making it challenging to achieve the required personal and community health levels. The project's objective was to determine whether a structured educational intervention for patients in Eldoret, Kenya, would increase diabetic knowledge and self-efficacy and reduce HbA1c levels. We utilized an experimental study with a convenience sample of 143 participants systematically grouped into control and experimental. The experimental group only received a structured educational intervention based on the health belief model. Pre- and post-intervention data for diabetic knowledge, self-efficacy, and HbA1c were analyzed using the independent T and ANOVA tests. We observed significant between-group differences for diabetic knowledge (t (116) = 7.22, p<0.001), self-efficacy t (96)=5.323, p<0.001; and HbA1c level t (121) =-2.87, p =.003. We also observed significant within-group differences for diabetic knowledge, t (12.6), p<0.001); self-efficacy t (5.32), p<.001); and HbA1c, t (4.4), p<0.001, in the experimental group only. This study reveals the effect of a structured education intervention in increasing diabetic knowledge and self-efficacy while reducing HbA1c levels in T2DM patients in Eldoret, Kenya.