The purpose of this quasi-experimental research was to evaluate the effects of a discharge planning program on the self-management ability of asthmatic patients attending a hospital emergency unit in the unrest area of southern Thailand. Sixty-four asthmatic patients who attended the emergency unit of Yala Hospital during November 2007 to December 2007 with acute symptoms were randomly selected. The patients attending on odd-numbered days were recruited as a control group and those who attended on even-numbered days were recruited as the experimental group. The intervention was a discharge planning program covering self-management in case of a sudden asthmatic attack. The instruments for data collection were a questionnaire assessing the self-management ability of asthmatic patients and a 48 hours revisit record. The instruments were content validated, and reliability tested by test-retest, yielding a correlation coefficient of 0.80. The scores were compared between the groups using independent t-test, and the 48 hours revisit records were compared using chi-square test. The results showed that the mean score of total self-management ability of the experimental group receiving the discharge planning program was statistically significantly higher than that of the control group (p<0.001). The percentage of 48 hours revisits in the experimental group was significantly lower than in the control group (28.1% vs. 81.3%) (p<0.05). The results of this study indicate that it would be useful to develop a discharge planning program for asthmatic patients in the three border provinces of southern Thailand.