Long-term monitoring of physiological and psychosocial variables would be beneficial to investigate slowly developing deterioration in wellness status of a subject. We designed a personal wellness monitoring system (TERVA), which allows monitoring wellness-related variables at home for many weeks or even months. The TERVA system runs on a PC computer and interfaces with different measurement devices through serial interface. Measured variables include beat-to-beat RR intervals, activity level, blood pressure, weight, temperature, respiration, ballistocardiography, movements, and sleep stages. In addition, self-assessments of daily wellbeing are stored by keeping a behavioral diary. To test the system, one healthy man was monitored for 10 weeks and an aged woman was monitored for 2 weeks. The data allows conclusion that the TERVA system provides a method to investigate wellness-related data over several weeks or even months in out-hospital conditions.