This article is one of the first to examine how the use of fixed‐term employment contracts (FTCs) affects firm competitiveness (i.e. productivity, wages and profits) while controlling for key econometric issues such as time‐invariant unobserved workplace characteristics, endogeneity and state dependence. We apply dynamic panel data estimation techniques to detailed Belgian linked employer–employee data covering all years from 1999 to 2010. Results show that the effects of FTCs on firm competitiveness vary across sectors: while temporary employment is found (at the 10 per cent significance level) to enhance productivity and profits in (labour‐intensive) services, this is not the case in manufacturing and construction.