This paper is concerned with competition in the peruvian manufacturing industry. A simple model of competition is estimated in order to evaluate the influence of productivity changes and relative labor costs. With this purpose an index of competition was constructed for 32 industrial branches, with export and import data, following the revealed comparative advantages methodology. The period of analysis goes from 1985 to 1995. The labor costs are measured in current dollars. Hence, the exchange rate effects on the competitiveness of the industrial branches are taken into account by the labor cost variable. The model also includes an index of capacity utilization in order to estimate the net effects of productivity and labor cost on the industrial competitiveness. One of the most striking results of this research is that only 8 industrial branches out of 32 considered, won competitiveness during 1985-1995. The trade liberalization and the exchange rate overvaluation are the main responsible for the massive lost of industrial competitiveness during 1991-1995.