The purpose of this paper is to conceptualise the extent to which partnerships with non-governmental organisations (NGOs) are a necessity for successful efforts of businesses in the area of corporate social responsibility (CSR). The main findings are based on an analysis of existing literature on NGO typologies and strategies for CSR and illustrated with examples from the Dutch National Research Program on CSR. Based on three different strategies towards CSR, the suggestion is that NGOs tend to become involved in partnerships with companies that have an interest in postponing concrete results, while partnerships with companies that have the potential for the biggest contribution to the ambitions of NGOs have the highest risk of diminishing NGO-legitimacy.