Background and Purpose: Effective diabetic foot ulcer (DFU) management critically involves wound care, pain management, and the development of patients’ self-management skills. This study aimed to evaluate the effect of nursing care based on the Orem Self-Care Model on pain, activities of daily living, and wound size in patients with DFUs. Methods: This experimental control group study was conducted with 66 patients diagnosed with grade 2 DFU according to the Wagner classification. Data were collected using an Introductory Information Form, the Modified Barthel Index, and the Numerical Rating Scale. Statistical analysis utilized Mann–Whitney U, Wilcoxon Signed Rank Test, and Friedman Repeated Measures Analysis of Variance on Ranks tests. Results: At the study’s outcome, no significant differences were found between the groups in terms of sociodemographic characteristics and disease data (p >.05). The Modified Barthel Index scores of the experimental group increased significantly each week, notably exceeding those of the control group in the third and fourth weeks (p <.05). Pain scores in both groups decreased significantly over time (p <.0001). Although the control group’s pain scores were statistically significantly lower than the experimental group’s in the second and third weeks (p <.05), this difference was not observed by the fourth week (p >.05). Although the wound area was initially higher in the experimental group, the wound healing rate in the experimental group (54.6%) was calculated to be higher than in the control group (35.6%).