Introduction Our aim in this paper is to explore key influences on the effectiveness of regional scrutiny arrangements. The creation of a scrutiny role for the English Regional assemblies in relation to their respective Regional Development Agencies (RDAs) comes after the establishment of overview and scrutiny committees within local government and the introduction of health scrutiny. The Labour government contends that scrutiny assists in plugging the`accountability gap'. However, prior research on scrutiny demonstrates that it has several key limitations as an instrument of accountability. For example, a review of the literature on parliamentary select committees suggests that they have struggled to scrutinise the work of the executive effectively (Ashworth et al, 2001a; Garrett, 1992; Polidano, 2001). In this paper, we identify five variables which currently influence the effectiveness of parliamentary scrutiny and argue that these variables have important implications for the success of regional scrutiny. RDAs were created in order to address an economic deficit. However, the government recognised that creating these regional quangos would further exacerbate the democratic deficit (Morgan, 2002). Consequently, it was proposed that the scrutiny of RDA plans, strategies, and performance would be a key function performed by regional assemblies, which were established``to add a (thin) veneer of regional accountability'' (Jeffery and Mawson, 2002, page 715). The regional scrutiny role originates from the 1988 Regional Development Agencies Act, which states that each RDA must``have regard, in the exercise of its functions, to any views expressed by the chamber, and to consult the chamber in relation to the exercise of such of its functions'' (section 8). However, RDA functions and budgets have continued to expand. Determining that further expansion should be accompanied by enhanced scrutiny, the government outlined a more substantial scrutiny remit in March 2001 in the consultation paper