Leaders of today need to achieve well in terms of task performance, perceiving low stress, and having high levels of work engagement. One may ask whether trait-based leadership resource factors can be identified and how such resource factors might relate to task performance, perceived stress, and work engagement. Our aim was to test the hypothesis, derived from Hobfoll’s motivational Conservation of Resources (COR) theory, that there are trait-based leadership resource factors, which are differentially correlated to the leaders’ task performance, perceived stress, and work engagement. Leaders (N = 344) aged from 23 to 65 years (M = 49, SD = 8.6; 58% women) completed an online questionnaire including measures of task performance, perceived stress, work engagement, personality traits, trait emotional intelligence, empathy, performance-related self-esteem, compassionate and rational leadership competence, and coping resources for stress. Using exploratory factor analysis, we identified four trait-based leadership resource factors. With Bonferroni adjustment, and controlling for sex, age, number of years in the current managerial position, self-deceptive enhancement, and impression management, only Rational Mastery was significantly positively correlated with task performance. Rational Mastery, Efficient Coping, and Modesty were negatively correlated with perceived stress, and all factors except Modesty, but including the fourth (Good-Heartedness) were positively correlated with work engagement. Organizations striving for sustainable work conditions should support trait-based leadership, which depends not only on a task-oriented resource such as rational mastery, but also on human-oriented resources such as efficient coping, modesty, and good-heartedness, all of them being differentially related to task performance, perceived stress, and work engagement.