The personality traits of social work leaders are important factors influencing ethical decision-making in organisations. The lack of empirical evidence with regard to the relationship between personal authenticity and ethical decision-making in social work stimulated the present study. Two hundred thirty-eight leaders (81.9% female) from organisations working in various fields of social work were administrated with the Authenticity Scale, Managerial Ethical Profile, and conducted two free association tasks with the cue words authenticity and self. Authenticity was positively correlated with ethical decision-making. In contrast, authenticity was not correlated with the tendency to make decisions in an effort to maximise economic profit for the organisation. The results of the present study have important practical implications for the social work sector. The positive correlation of authenticity with ethical decision-making indicates that positive reinforcement of authenticity in leaders could possibly lead to supporting ethical decision-making within an organisation. Therefore, supporting authenticity in leaders working in social work may also help foster quality services and prevent unethical behaviour.