Despite the popularity of leadership research, there is not consensus about what kind of positive psychological interventions (PPIs) are effective in different organizations and settings. This is important to identify key empirical evidence regarding positive leadership interventions. The EU Horizon 2020 “H-WORK” project aims to design, implement and validate effective interventions to foster workplace mental health in SMEs and public organizations. Based on a stepwise approach towards achieving this goal, different PPI pilot studies have been tested in order to replicate in these type of organizations.The aim of the study is to explore the impact of Positive Leadership Interventions on wellbeing and performance variables. In Study 1, 41 managers in an automotive company received a leader-as a-coach training workshop and individual coaching sessions. In Study 2, the study was replicated in a different organization with 9 nuns, with whom different positive leadership styles were trained. In both studies, participants were divided into Experimental (EX) and control-Waiting List (WL) groups. Results were mixed and successful in increasing all the study variables (leader-as a-coach skills, work engagement and performance) compared to WL in Study 1. In Study 2, results indicated that transformational, authentic and coaching-based leadership, and psychological capital levels increased significantly from Pre to Post. Results suggest the need of more replication studies on PPIs in leadership skills. Finally, the relevance of culture, organizational context and management in the replication studies on PPIs with leaders is an emerging topic for future research and practice.