Patients with cardiovascular disease have been increased dramatically, thus, an issue arose for those who received percutaneous coronary intervention, because of the shorter of length of stay in hospital resulted in a limited continuum care of cardiac rehabilitation. This study aimed to examine the relationship among the variables ”physical activities”. ”uncertainty” and ”health self-efficacy”. A correlation study with convenience sampling was used and 108 subjects recruited from an out-patient department of a regional hospital. The results showed that the lower score of ”uncertainty in illness”, the higher of ”health self-efficacy” and the better of ”physical activities”. Nurses should assess patients' ”uncertainty in illness” after PCI, and provide appropriate nursing instructions to promote clients' health self-efficacy. (Tzu Chi Nursing Journal, 2012; 11:3, 66-76)