This study examined the effect of planned happenstance skills on the career development which is nowadays actively discussed in the field of career counseling. It was investigated that how the relationship between career aspiration and career exploration behavior is changed on the level of planned happenstance skills including curiosity, persistence, optimism and risk-taking. Correlation analysis and moderation effect analysis were conducted to convey this purpose. As a result, three variables showed significant inter-correlations. Moreover, planned happenstance skills moderated the relationship between career aspiration and career exploration behavior. These results suggest that even though one has high engagement in their career development, concrete exploration behavior cannot be manifested without planned happenstance skills. Finally, it is discussed how happenstance theory can be applied on career counseling field.