Key account management has been highlighted as a significant area of academic research (Leigh and Marshall 2001, Workman et al. 2003) and both managers and academics alike are of the view that suppliers need to develop long-term relationships with selected strategic customers. Despite a recent academic focus on Key Account Management, there have only been a limited number of published studies on the individual Key Account Manager (KAM) (Sengupta et al. 2000, Schultz and Evans 2002, Guenzi et al. 2007, 2009) and it remains an under-investigated research area (Guenzi et al. 2009). This paper endeavours to explain the underlying factors underlying Key Account Manager relationship performance serving to expand extant literature in key account management.