This paper examines the effects of equity ownership by insiders and equity ownership by blockholders and institutions on performance using samples of firms from four countries (United States, United Kingdom, Germany, and Japan). While there are no consistent relationships between insider ownership or blockholder/institutional ownership on performance across the four countries, there are nevertheless significant associations between ownership of these groups and performance within the four countries. Our results may indicate that the effects of insider ownership and/or block-holders/institutions depend very much on local laws or the local business environment. In contrast, the effects of the control factors on performance are much more consistent. Leverage, for example, tends to have a negative effect while capital expenditures and sales growth both generally have a positive effect. (C) 2004 Elsevier B.V. All rights reserved.