This study investigated novice nurses' perception of the effects of preceptors' mentoring function on their self-efficacy and organizational commitment.Nursing mentoring is a mutually beneficial relationship between more and less experienced nurses. In nurse education, mentoring is a powerful tool that can be used for a successful transition from a novice to an experienced nurse.This descriptive study used a cross-sectional design.A questionnaire survey was conducted with 160 novice nurses from Korean general hospitals who had been working for less than a year after completing their preceptorship.The preceptors' mentoring function as perceived by the novice nurses was 3.87, self-efficacy of the novice nurses was 3.71 points, and the organizational commitment was 3.46 out of 5 points. The results of the multiple regression analysis showed that mentoring function significantly affected novice nurses' self-efficacy (β = 0.50, p < 0.01) and organizational commitment (β = 0.54, p < 0.01). Further, the preceptorship training period had a significant effect on organizational commitment (β = 0.13, p < 0.05).Preceptors' mentoring function, as perceived by novice nurses, affected their self-efficacy and organizational commitment.