In highly structured organisational fields individual efforts to deal rationally with uncertainty and constraints tend to lead, in the aggregate, to greater homogeneity in structure, culture and output. Drawing on institutional theory, this paper develops research propositions regarding the nature and scope of corporate social responsibility (CSR) engagement at trade/industry association level. The cases of the water and sewerage and film industries are used in order to test these propositions. The findings suggest that (a) trade associations in more homogeneous industries are more likely to engage with CSR-related issues; (b) trade associations in industries that face greater external scrutiny and threats to legitimacy are more likely to engage with CSR-related issues; and (c) trade associations are more likely to engage with those substantive CSR issues that are of greater concern to the industry's most salient stakeholders. The findings also suggest that trade associations may have a greater tendency to engage in symbolic legitimation efforts through CSR if faced with the task of repairing industry legitimacy.