The present study aimed to investigate the development and interplay of emotional stability and affective self-regulatory efficacy beliefs through adolescence to young adulthood. A latent growth curve approach was used to investigate level and stability of emotional stability and self-efficacy in managing negative emotions and in expressing positive emotions. We found that initial levels of emotional stability and self-efficacy beliefs are highly correlated. In accordance with the posited hypothesis, the growth rate of perceived self-efficacy in managing negative emotions predicted the growth rate of emotional stability, whereas the opposite path was not significant. The growth rates of perceived self-efficacy in expressing positive emotions and emotional stability were not related to each other. Taken together, these findings point to self-efficacy beliefs as instrumental to the change of traits. Practical implications of results are discussed, highlighting the role of social cognitive theory in supplying the proper strategies to design effective interventions to enable people to make the best use of their potentials. Copyright © 2012 John Wiley & Sons, Ltd.