This article contributes to the understanding of why some management experiences of non-family CEOs (NF-CEOs) in privately owned family firms (POFFs) are successful, while others are not. It uses the flexible pattern-matching technique to examine seven case studies of POFFs with different experiences in recruiting NF-CEOs. Drawing on human capital specificity and heterogeneity, as well as socio-emotional wealth perspectives, our analysis suggests that NF-CEOs and owning families must invest time to gain knowledge of each other. Consequently, longer minimum tenures are required compared to non-FFs, making the alignment of NF-CEO and successor life cycles crucial for success. A cooperative and long-term-oriented personality of NF-CEOs is also relevant to fit the context of family businesses. This article is the first to adapt the specificity of human capital theory to the study of NF-CEOs.