When people undergo stressful situations such as a cancer diagnosis, they ask, "why me?" The causal attributions people make about cancer influence what kind of coping strategies are chosen. Weiner (1979) suggested three dimensions of causal attributions: focus of causality, stability, and controllability. The purpose of the present study was to test the relation between causal attributions and self-efficacy in patients with cancer. The subjects were 194 patients who had been diagnosed cancer one year ago and attended an outpatient clinic. 1. Each mean score of causal attribution dimensions (focus of control, stability, controllability) that each patient made about cancer was 2.47, 2.73, 2.86, 3.35, and 3.28. The mean score of self-efficacy was 71.03. 2. There was a significant negative correlation between self efficacy and controllability. Particularly, there was a significant negative relationship between self efficacy and external controllability. Based upon these results, it is recommended that the developing nursing interventions to change causal attribution and self-efficacy is necessary. A number of theoretical relationships and empirical finding are confirmed by this data, and future proposals in research is suggested.