There are many ways in which opposition to, or distaste for, the production of armaments and other equipment used for military purposes can be expressed. The purpose of this paper is to introduce to the peace studies literature the possibility that such views can find expression in the construction of equity investment portfolios. In particular, the paper examines the relative importance of military contracting as one area of possible concern to `ethical' or `socially responsible' investors in Britain. First, it is found that virtually all the managed investment funds marketed to British investors as possessing ethical characteristics make some exclusion on the basis of involvement in military contracting. The various ways in which military contracting is defined by the funds are outlined and discussed. The second substantive section of the paper then examines the attitudes of 125 users of an ethical information service and finds that military contracting is one of the highest ranked categories, but that the concern is primarily with the supply of non-civilian rather than civilian items. The discussion then briefly considers: experience in, and prospects for, other countries; further possible definitions of unacceptable military contractors; and some of the implications for the composition of equity portfolios.