Short-term relaxation responses to a mobile phone based voice guided relaxation (SelfRelax) and a self-guided relaxation are studied. The relaxation responses are measured with state-trait anxiety inventory's form Y-1 (state), blood pressure, heart rate, and heart rate variability features (HRV). Data from fourteen subjects and 73 relaxation sessions were included in the analysis. Relaxation sessions were made in two days during normal daily life. The relaxation decreased STAI Form Y-1 scores by 5.5 points on average when pre- and post-relaxation levels were compared. Small differences were observed between the two relaxation methods. Systolic blood pressure decreased significantly with both relaxation methods in subjects whose pre-relaxation pressures were >140 mmHg. Data collected with a beat-to-beat heart rate logger turned out to be poor quality and were analysed as separate cases. Overall, the subjects gave positive feedback on the mobile phone application. (15 refs.)