Using longitudinal data on immigrants in the Netherlands for the years 1991, 1994, 1998, 2002, we examined the impacts of social contacts and Dutch language proficiency on adult foreign-born men's earnings, employment and occupational status. The main conclusions are as follows. On average, social contacts and a good mastery of the Dutch language enhance immigrants' economic performances. The effects are stronger for immigrants with low-skill-transferability than for immigrants with high-skill-transferability, and are stronger for economic migrants than for non-economic migrants. Contact with Dutch people and Dutch organisations unambiguously enhances all aspects of immigrants' economic performance, however, we found no evidence for the positive effect of co-ethnic contact on employment status.