Work and family have for long been considered to be the main life spheres of individuals (Zedeck, 1992). Whereas it has been normative to keep work and family spheres apart (Ashforth, Kreiner & Fugate, 2000; Zerubavel, 1991), nowadays, the boundaries between the two are considered fluid indicating that elements navigate from one sphere to the other. This has been referred to the blurring of work and family domains and to the permeability of boundaries, leading to work-to-family and to family-to-work permeability (Frone, Russell & Copper, 1992; de Man, de Bruijn, & Groeneveld, 2008). In the context of a family business, work and family are de facto spatially and temporally hard, or even impossible, to separate where the boundaries between family and business are highly permeable. Permeability as well as its positive and negative consequences have been largely discussed in regards to “stress” and “energy” spilling over into the other sphere and/or crossing over to someone else’s sphere (see Westman, 2006). Permeability can relate to any elements that may navigate between the spheres, above all emotions (Languilaire, 2009). Emotions are central for the family business and due their permeability of domains may be affected by family emotions and vice-versa (see: Sharma, 2008; Björnberg & Nicholson, 2008; Brundin, Florin-Samuelsson & Melin, 2008). Studies have illustrated that emotions navigate between work and family and research on work-life conflicts is full of illustrations of the positive and negative spillover of emotions and their consequences in one or the other sphere. For example, happiness emerging from the workday may get transported to the dining table, anxiety about the family may affect one’s attitudes at work and frustration emerging from a Friday work meeting may affect one’s mood during the weekend. Haag and Sund’s (2015) research on divorce indicates the positive and negative spillover of emotions and their consequences in one or the other sphere of the family business. Likewise, Brundin and Sharma (2011) explain how the strong link between the family and the business spheres can lead to emotional messiness with a mix of positive and negative emotions at the same time related to the same issue, such as both loving and hating one’s sibling who is also the CEO. To manage such emotional messiness and to get a sense of balance between work and family, boundary management strategies can be developed (see Bulger, Matthews, & Hoffman, 2007; Kossek, Lautsch, & Eaton, 2005, Languilaire, 2009). Based on Ashforth et al., (2000) some family members may develop an integrating boundary management strategy based on a higher level of permeability to facilitate the integration of and the transition between work and family. By contrast, others may develop segmenting boundary management based on a lower level of permeability to avoid elements to transit between the spheres. In this context, family members may differently experience the permeability between family and work spheres in regards to their emotions between the two spheres: work and family. In that regard, work and family are characterized by different emotion rules (Hochschild, 1983) leading to the emergence of emotion boundaries (Languilaire, 2009). The central point of such rules is that “being emotional” and to show emotions is socially “appropriate” and “natural” in the private sphere whereas it is depicted as socially “inappropriate” or even “irrational” in the public sphere (see Hochschild, 1983; White & Brown, 1991). People are expected to behave emotionally different at home and at work by creating, developing and maintaining emotion rules and emotion boundaries in the work and the family spheres (Languilaire, 2009). As a whole, whereas any individual may be affected by emotion rules, the context of family businesses is particular and studies on such permeability is largely neglected, especially in relation to emotion aspects. As work and family are de facto so interwoven in family business, emotion boundaries may be blurred. The purpose of this paper is to explore family members’ creation and management of emotion rules and boundaries in the context of a family business and their implications. Our results have implications for the cohesion and the emotional climate of the family, which may in the end affect the family firm performance.