Treating suicidal clients with borderline traits can be conducive to burnout. Dialectical behavior therapy (DBT) may assuage this burnout in counselors. As part of a DBT treatment outcome study, 6 counselors in training collected their own salivary cortisol samples and completed self-report measures of burnout and well-being for 1 year. Findings indicate a significant interaction for cortisol levels by treatment condition, such that DBT counselors experienced less physiological stress over time relative to a control group of counselors. There were no group differences in self-reported burnout or well-being. DBT may have a salutary effect on trainees' physiological stress levels over time.