AIM: The current study was conducted to determine the effectiveness of group therapy based on acceptance and commitment for nursing students' procrastination and perfectionism. BACKGROUND: Procrastination and perfectionism are two growing problems among nursing students that threaten their academic success. Therefore, it is necessary to identify interventions to alleviate these issues. DESIGN: A parallel randomized controlled trial. METHODS: Sixty-five nursing students were selected using a convenience sampling method and randomly assigned to intervention and control groups. The intervention group received group therapy based on acceptance and commitment in eight sessions. Data were collected using the Procrastination Assessment Scale for Students and Perfectionism Inventory before, immediately after, and eight weeks after the implementation of group therapy. Descriptive statistics and inferential tests were used to analyze the data. RESULTS: Students' academic procrastination decreased significantly over time, with students in the intervention group reporting 5.817 units of academic procrastination lower than the control group (P = 0.038). On the other hand, the adaptive perfectionism of students in both groups did not change significantly over time. Nevertheless, adaptive perfectionism among students in the intervention group was 2.854 units higher than that of the control group (P = 0.010). Additionally, the changes in maladaptive perfectionism between the two groups of students over time were not significant. However, students in the intervention group experienced 1.485 units lower in maladaptive perfectionism compared to the control group (P = 0.215). CONCLUSION: Therefore, it is recommended that group therapy based on acceptance and commitment be utilized to reduce academic procrastination among nursing students.