In recent years, university students’ employment has become an increasingly prominent problem worldwide. Improving the job search clarity of students is a great way to boost job-hunting success. Proactive personality may predict job search clarity through the mediating effects of core self-evaluation and career exploration. However, few studies have explored this relationship and the mediating roles of core self-evaluation and career exploration. To identify the relationship between a proactive personality and job search clarity and the mediating roles of core self-evaluation and career exploration, a cross-sectional survey was conducted. A total of 495 students majoring in nursing completed the questionnaire which consisted of the proactive personality scale, core self-evaluation scale, career exploration survey, and job search clarity scale. Correlation analyses and mediation analyses were conducted using SPSS 24.0 and AMOS 24.0 respectively. This study showed that students higher on the proactive personality scale were more likely to perform better on job search clarity. Core self-evaluation and career exploration have fully mediating effects on the relationship between a proactive personality and job search clarity. Therefore, interventions concentrated on cultivating proactive personality, improving core self-evaluation, and strengthening career exploration would be necessary for increasing job search clarity.