National Asthma Education and Prevention Program (NAEPP) suggests using asthma action plans for patient self-care. Recent studies reported that many asthma patients had difficulties in following action plans on a daily basis and had low compliance to medication regimens. The goal of our study was to design and evaluate the Home Asthma Telemonitoring (HAT) system aimed to help asthma patients to follow their self-care plans according to the NAEPP recommendations. Our study resulted in the development of the system which provided patients with continuous individualized help in the daily routine of asthma self-care and notified heath care providers if certain clinical conditions occurred. This allowed early recognition of potentially dangerous situations and timely intervention. The evaluation of the HAT system underwent several stages. First we showed, that the HAT system provides reliable reciprocal exchange of all relevant information between a physician and asthma patient in home settings. Further evaluation demonstrated that lung function test results collected during home asthma telemonitoring are comparable to those collected under the supervision of trained professionals, and Internet-based home asthma telemonitoring can be successfully implemented in a group of patients without previous computer experience. Preliminary results of an on-going HAT evaluation showed higher patient compliance to asthma action plans in comparison to the compliance reported for patients in standard care. The clinical impact of HAT on asthma outcomes is being currently evaluated in a randomized clinical trial funded by NIH. HAT has a potential for improving clinical outcomes and quality of life in the studied patient population and may be a model for monitoring and self-management of patients with other chronic health conditions.