Veterans experience mental health conditions at a disproportionate rate compared to their civilian counterparts, and approximately 60% of older veterans who receive their care through the United States Department of Veterans Affairs (VA) do not meet physical activity (PA) recommendations. We tested the Veterans as Foster Ambassadors program at the VA Maryland Health Care System to examine whether fostering a companion dog would improve PA and function, heart rate variability (HRV), balance, and quality of life (QOL) in older veterans. Participants wore an accelerometer for >/=10 days during each phase (30 day baseline vs. 60 day foster period) to measure daily PA (n = 4). Six-minute walk (6MW) and balance testing (n = 4) and 24 h heart rate (HR) and HRV (n = 2) were determined at baseline and during the foster period. Compared to baseline, there were significant increases in (a) distance during the 6MW, (b) daily steps, and (c) time spent in moderate activity during the foster period. 24 h HR decreased and time- and frequency-domain measures of HRV significantly increased in a veteran with post-traumatic stress disorder during the foster period compared to baseline. All veterans offered positive feedback about the program and indicated that it was beneficial to them. The results from this pilot study provide evidence that fostering a companion dog can improve PA, health, and QOL in older veterans. Future research conducted with a larger sample size to validate the results is warranted.