Purpose: To determine the effects of progressive muscle relaxation exercise (PMRE) on clinical stress and burnout in student nurse interns. Design and methods: This is a randomized controlled trial. Interns were divided into control group (CG; n = 78) or experimental group (EG; n = 67) randomly. PMRE was performed by students in the EG. Personal information form, Burnout Measure Short Version (BMS) and Physio-Psycho-Social Response Scale (PPSRS) for nursing students were administered to both groups in the first and last meeting. Findings: There was a significant difference in posttest scores between groups; EG posttest scores on the BMS, on the PPSRS, and subscales were lower than those of the CG. Practice implications: PMRE training ameliorates burnout and PPSRs to stress during clinical practice in nursing students.