The impact of competition on productivity growth is investigated using a panel of observations for 2,000 enterprises in Dutch manufacturing (1978-1993). An output equation is estimated which includes besides factor inputs the firm's market share and a firm-specific growth trend as explanatory variables. The growth trend is assumed to be determined by market concentration (Herfindahl index), export share, share of competing imports, profitability, firm size and net entry rate. Low market concentration, high export share and high share of competing imports appear to have a positive impact on productivity growth. This confirms that competition improves factor productivity growth. Besides, profitability appears to be conducive to productivity growth. The impact of firm size and net entry on productivity growth are generally insignificant. Keywords: Productivity growth ; Competition ; Market structure ; Manufacturing ; The Netherlands