This study was done using a Quasi-experimental research design to determine the effects of social support on compliance with sick role behavior in hypertensive patients and to know if the effect of the social support on compliance lasted for at least 6 months. The subjects consisted of 81 hypertensive patients who were registered in the Cardio-Vascular OPD at Chonnam National University Hospital. They were divided by random sampling into 42 people for the experimental group and 39 for the control group. Data were gathered from June 3, 1996 to June 10, 1997 through individual interviews using a structured questionnaire. The results of the study were summarized as follows : 1. Compliance with sick role behaviors in hypertensive clients was significantly increased in the experimental group who received social support from the nurse as compared to the control group who did not receive social support(t=15.99, p<.001). 2. The effect of social support on compliance with sick role behaviors in hypertensive clients lasted for 6 months(t=7.99, p<.001). 3. Four of six people stopped smoking in experimental group after the intervention of social support, but none of the five in control group were able to stop smoking. Fisher's Exact test showed a significant difference between the experimental and control group(x2=4.385, p<.05). Mantel Haenszel test showed that the effect of social support on stopping smoking in the experimental group lasted for six months because there were no significant differences between one month after the social support and six months after, in the number of subjects who stopped smoking(x2=1.154, p>.05). Finally, social support was effective on compliance with sick role behaviors and stopping smoking in the hypertensive clients, and the effect of social support on compliance lasted for 6 months.