The second most common cancer case in Indonesia is breast cancer which its healing is difficult to be predicted. The breast cancer sufferers undergo uncertainty, depression, and psychological pressure. This condition decreases the patient’s optimism of healing. This research aimed to identify factors affecting the breast cancer patients’ optimism of healing. This study applied cross sectional design with 96 respondents. Factors affecting significantly against respondents’ healing optimism were social support (p value = 0,015) and stress (p value = 0,022). The most influencing factor was social support (â = 0,055). It is recommended that the further research will be more focused on the nursing intervention that used to raise social supports for breast cancer patients.