We investigate the relation between perceived competition and voluntary disclosure in the absence of capital market incentives by examining private UK companies, which have the option to withhold sales and costs of sales information from their publicly-filed accounts. We survey managers about their companies' competitive environments and we calculate archival measures of industry competition. We find that managers are more likely to withhold information about sales and costs if they perceive that current or potential competition is strong. Consistent with disclosure being costlier for successful firms, we also find that more profitable companies are more likely to withhold information. (C) 2009 Elsevier B.V. All rights reserved.