A randomized, controlled trial was conducted to assess the effectiveness of Blue Angel for Asthma Kids, an Internet-based interactive asthma educational and monitoring program, used in the management of asthmatic children. One hundred sixty-four (n = 164) pediatric patients with persistent asthma were enrolled and randomized into two study groups for a 12-week controlled trial. The intervention group had 88 participants who were taught to monitor their peak expiratory flows (PEF) and asthma symptoms daily on the Internet. The also received an interactive response consisting of a self-management plan from the Blue Angel monitoring program. The control group had 76 participants who received a traditional asthma care plan consisting of a written asthma diary supplemented with instructions for self-management. Disease control was assessed by weekly averaged PEF values, symptom scores, and asthma control tests. Adherence measures were assessed by therapeutic and diagnostic monitoring. Outcome was assessed by examining quality of life and retention of asthma knowledge. The data were analyzed by comparing results before and after the trial. At the end of trial, the intervention group decreased nighttime (-0.08 ± 0.33 vs. 0.00 ± 0.20, p = 0.028) and daytime symptoms (-0.08 ± 0.33 vs. 0.01 ± 0.18, p = 0.009); improved morning (241.9 ± 81.4 vs. 223.1 ± 55.5, p = 0.017) and night PEF (255.6 ± 86.7 vs. 232.5 ± 55.3, p = 0.010); increased adherence rates (p < 0.05); improved well-controlled rates (70.4% vs. 55.3%, p < 0.05); improved knowledge regarding self-management (93.2% vs. 70.3%, p < 0.05); and improved quality of life (6.5 ± 0.5 vs. 4.3 ± 1.2 on a 7-point scale, p < 0.05) when compared with conventional management. The Internet-based asthma telemonitoring program increases self-management skills, improves asthma outcomes, and appears to be an effective and well-accepted technology for the care of children with asthma and their caregivers.