Objective <p>To evaluate whether Skinner’s programmed instruction approach is more effective than traditional lecture-based teaching in improving diabetes-related knowledge, technical skills, self-efficacy, and patient satisfaction among undergraduate nursing students.</p> Methods <p>This randomised controlled trial was conducted at a tertiary teaching hospital in China. A total of 80 nursing students were randomly assigned to either a control group (traditional teaching, <i>n</i> = 40) or an experimental group (programmed instruction, <i>n</i> = 40). The intervention lasted 4 weeks. Outcomes were assessed across four domains: diabetes knowledge, technical skills (insulin injection and blood glucose monitoring), self-efficacy, and patient satisfaction. Composite scoring was used to estimate effect size and clinical relevance.</p> Results <p>Following the intervention, the experimental group demonstrated significantly higher scores than the control group in diabetes knowledge, insulin injection accuracy, and blood glucose monitoring skills (all <i>P</i> &lt; 0.05). General Self-Efficacy Scale scores also improved significantly in the experimental group (<i>P</i> &lt; 0.05). Patient satisfaction ratings were significantly higher in the experimental group across service attitude, technical ability, and health education guidance (<i>P</i> &lt; 0.05).</p> Conclusion <p>Programmed instruction can effectively enhance nursing students’ diabetes knowledge, technical skills, and self-efficacy, while also improving patient satisfaction. This teaching model shows promise for broader application in clinical nursing education.</p>