The construction industry is among the most hazardous industries, with a fatality rate in Europe 3.4 times higher than average. While the occupational safety and health (OSH) coordinator has been a key actor in European efforts proposed to improve OSH in the industry since 1992, it is important to study the competences needed for the successful coordination of OSH in the construction industry. Existing literature on OSH coordinator competences are examined, and an expert survey is used to identify the competences characterising the most successful coordinators in Denmark. Finally, observational case studies of the perceived most successful coordinators in the Danish construction industry are used to exemplify the newly identified competences. The most frequently mentioned competences, not covered in previous research, are "innovativeness," "having overview," "persistency," "thoroughness," "sociability," and "being systematic." The results demonstrate the important "practice of knowing," rather than possessing formal knowledge, education, and/or skills. The most important practice of knowing for the coordinators is likely that of the ability to transfer knowledge into practice. Future research, education and legal requirement in this field could benefit from a focus on what practices of knowledge actually work in real-life settings, rather than focussing on idealistic notions of these qualities.