Objectives: This study aimed to identify the mediating effects of distress tolerance and self-directedness on the relationship between grit and problem-solving ability in nursing students.Methods: Participants were 335 nursing students in two universities between September to December 2018. The data were analyzed using a t-test, one-way ANOVA, and Person’s correlation coefficients. In addition, Baron and Kenny’s method was used to analyze mediating effects of distress tolerance and self-directedness between grit and problem-solving ability.Results: Significant correlations were found between grit and problem-solving ability (r = 0.57, <i>p</i>< 0.001), between grit and distress tolerance (r = 0.38, <i>p</i>< 0.001), and grit and self-directedness (r = 0.46, <i>p</i>< 0.001). There were the mediating effects of distress tolerance (z = 5.37, <i>p</i>< 0.001) and self-directedness (z = 7.25, <i>p</i>< 0.001) on the relationship between grit and problem-solving ability.Conclusions: It is necessary to develop and apply the programs that strengthen distress tolerance and self-directedness to improve nursing students’ problem-solving ability.