This paper examines the determinants of small establishment shares in Greek manufacturing and compares the results to previous findings for U.S. small firms. Two groups of explanatory variables are used: Industry variables and small-firm performance variables. Both types of variables are found to have an impact on the determination of small firms shares, with performance variables being at least as strong as industry variables. Measures of entry barriers give mixed results. Capital intensity exercizes an expected negative impact. Advertising intensity shows a trace of positive impact for medium-sized establishments in consumer goods sectors. Operating efficiency of small firms also appears as a strong influence on their shares whereas investment intensity does not appear significant. These results are in partial agreement to earlier findings for U.S. small firms. Their generality is tempered both by the fact that they come from a small country of middle level of development and by the recognition that the year of observation (1983) was at the start of Greece's industrial adjustment to entry in the EEC. Both these concerns constitute areas of future research.