This study examined the direct and indirect influences of school leadership, institutional safety and professional learning and teaching climate on in-service teachers' human capital development. To this purpose, correlational design with structural equation modeling was employed. The data were collected from 379 randomly selected in-service teachers in primary schools using six-point Likert-type scale. Internal consistency and composite reliability coefficients for all constructs were above 0.80. The constructs had adequate convergent and discriminant validities. Confirmatory factor analysis was performed using AMOS software to validate the measurement model. The model fit indices showed a good fit of measurement model and structural model to the data. Results showed that professional learning-teaching climate has a relatively stronger influence on teachers' human capital development compared to school leadership and institutional safety. Professional learning-teaching climate mediates the influences of school leadership and institutional safety on teachers' human capital development. After controlling institutional safety and professional learning-teaching climate, school leadership specifically exhibited a significant direct effect on human capital development. Likewise, institutional safety exhibited a significant direct effect on human capital development given controlled professional learning-teaching climate and school leadership. Thus, we conclude that the schools with shared leadership and safe institutional climate can foster in-service teachers' human capital development by establishing supportive professional learning and teaching climate that highly invests in continuing professional learning and development. To this end, establishing supportive professional learning-teaching climate for teachers is suggested to boost their human capital which in turn will enhance student learning and achievement.