Purpose: The purpose of the study was to identify the mediating effects of self-efficacy between academic stress and college adjustment in first year nursing students. Method: Data were collected from 396 first year nursing students from 3 junior colleges and analyzed using descriptive statistics, Pearson correlations and structural equation model (SEM) with PASW 18.0 and AMOS 18.0 programs. Results: There was a negative relationship between academic stress and college adjustment but a positive relationship between self-efficacy and college adjustment. There was a partial mediating effect of self-efficacy between academic stress and college adjustment. Conclusion: The results indicate a need to develop programs that effectively promote the self-efficacy of first year nursing students to decrease academic stress and maximize college adjustment. Further studies are needed in which other factors that could affect college adjustment are examined.