Stress worldwide is an important health issue, and there are many publications mention that plantar reflexology is an effective way to mitigate this issue. However, most publications offer only qualitative evidence. The research was designed to evaluate the effectiveness of a plantar reflexology insole in reducing stress. It is aimed at reproducing traditional manually applied therapies. It was used on a group of volunteers whose responses were measured before and after the application of active and sham therapies. The results indicate that the system does indeed produce quantifiable reductions of stress levels. The contributions were the design of a mechanical device that provides consistent levels of stimulation, while the evaluation of results was by quantitative measures of stress such as heart rate variability and blood cortisol instead of qualitative evaluations by questionnaires. The limitations were the reduced size of the population under study, while the conclusions are that the system is effective in treating stress.