Background <p>Design thinking (DT) is increasingly valued in nursing education for cultivating innovation and problem-solving skills. Although individual differences in DT competence are recognized, the pattern of change in these competencies over time remains unclear.</p> Methods <p>Ninety-six nursing students enrolled in a DT training course completed the Creative Synthesis Inventory–Taiwan (CSI–Taiwan) at four time points: before training, immediately after training, and one- and three-months post-training. Students were classified into higher- and lower-scoring groups using K-means clustering. Generalized Estimating Equations (GEE) were used to analyze changes in CSI–Taiwan scores over time.</p> Results <p>GEE analysis showed no significant differences in visualization, discovery, prototyping, and evaluation skills immediately after training. Both higher- and lower-scoring students demonstrated significant declines in all DT skills over time. The magnitude of decline was significantly smaller among higher-scoring students, except for the discovery skill between immediately after training and one-month post-training.</p> Conclusions <p>These findings align with Bandura’s self-efficacy theory, suggesting that efficacious self-beliefs in DT competence are reflected in differing patterns of change over time. Nursing curricula incorporating longitudinal, spiral models of DT instruction—such as project-based applications in clinical settings—may help consolidate and sustain DT skills, particularly among lower-scoring students.</p>