This study investigates the impact of coachee readiness for change and core personality traits as both criteria and predictors of outcomes after strength-based leadership coaching. Specifically this study examined developmental readiness, change readiness and core self-evaluations (CSEs; locus of control, neuroticism, self-efficacy and self-esteem), in the coachee to measure both their capacity to predict changes in transformational leadership and to act as outcome criteria in themselves after coaching. Thirty executives and senior managers from a large not-for-profit organisation were assigned to either a coaching or waitlist cohort using a between-subjects non-equivalent control group design. The coaching cohort received six sessions of leadership coaching involving feedback on leadership and strengths, goal setting and strengths development. After six sessions of coaching over three months, cohorts then switched roles. The results showed that participants in the waitlist first group declined in both developmental and coaching readiness whilst waiting for coaching. For the coaching first group their CSEs increased significantly over time but this was not the case for the waitlist first group. Only change readiness at Time 1 and CSEs at Time 2 were significant predictors of enhanced leadership effectiveness after coaching. The results suggest that these coachee variables are potential outcome criteria and predictors of change after leadership coaching.