Corporate governance guidelines in many countries do not specify the determinants of non-executive director compensation and the empirical evidence has only briefly and indirectly addressed this issue. We show that this question is fundamentally complex because (a) whilst the roles of non-executive directors are relatively well stated, their actual contributions remain unclear, (b) governance codes have not discussed the ways in which non-executive directors should undertake their roles and (c) non-executive director contribution may be unobservable. As a result, their efforts, contribution and/or performance are difficult to measure. Nevertheless, we find the literature related to non-executive directors strongly supportive of some sort of remuneration that is a function of performance and effort to align non-executive directors with their duties and make boards more efficient in undertaking their duties.