Purpose: This study was aimed to evaluate the effect of an internet community on knowledge, self-efficacy, and self-care behavior in workers with hypertension. Method: The research design used was a nonequivalent control group pre-test and post-test design. Sixty hypertensive workers participated in this study(Exp.=29, Cont.=31). The data was collected from the 3rd of November 2003 to the 27th of February 2004 using an interview with questionnaires. Information related to hypertension was provided on the internet community weekly and an e-mail newsletter was sent in order to increase participation in the internet community. We used a tool developed by Park Young-Im(1994) that measured knowledge related to hypertension and self-efficacy. A tool developed by Jung Mi-Young(2001) was used for self-care behavior. The collected data was analyzed with an $x^2-test$ and t-test using the SPSS WIN 10.0 program. Result: The internet community helped workers with hypertension to increase their knowledge related to hypertension, as well as increasing their self-efficacy and self-care behavior. Conclusion: An internet community could be applied as hypertensive nursing intervention.