Investigating the effects of privatization in transition countries is the focus of a large body of current research. Generally, privatization stimulates private sector development, attracts foreign direct investment, fosters competition and contributes to the formation of stock markets. In addition, privatization may improve individual enterprises’ performance. This paper investigates the impact of privatization on Ukrainian firms’ productivity. The empirical research is based on a sample of 466 Ukrainian joint-stock enterprises for the period of 1997 – 1999. Estimation results indicate that privatization positively influences labor productivity, but also that these effects diminish over time.