Objective: Research indicates that cognitive functioning is negatively impacted by exposure to chronic stress due to overactivation of the stress response. Yoga has demonstrated benefits when practiced by individuals diagnosed with posttraumatic stress disorder (PTSD). This quasi-experimental pilot study examined the impact of a yoga intervention on cognitive functioning, symptoms of PTSD, and the biological stress response in Veterans diagnosed with PTSD. Method: Cognitive functioning, self-report measures of mental health symptoms, and salivary cortisol were measured within two weeks prior to beginning and following completion of a 10-week yoga protocol. Veterans with PTSD participated in gender-specific groups of the yoga intervention. Paired t tests and correlational analyses were used to analyze quantitative data. Results: Statistically significant improvements were observed between baseline and postintervention scores on measures of response inhibition, PTSD, depression, sleep, quality of life, and subjective neurocognitive complaints. Positive correlations were found between baseline and postintervention changes in sleep and depression, and between change in cortisol output and a measure of life satisfaction. Statistically significant differences (baseline to postintervention) for other objective measures of cognitive performance and cortisol were not detected. Conclusions: Results provide preliminary support for the practice of yoga to improve cognitive functioning (response inhibition) related to symptoms of PTSD while also improving mental health symptoms, sleep, and quality of life. Positive correlations affirm the role of sleep in mood symptoms and indicate the need for further examination of the role of cortisol in life satisfaction. (PsycInfo Database Record (c) 2020 APA, all rights reserved).