A feed efficiency experiment was conducted in a population consisting of progenyfrom 10 full sib families of a cross between two broiler lines. Microsatellitegenotypes were determined on Generation (G) 1 and 2. In G3, BW at 23 and 48 dand feed intake were measured and were used to calculate growth between 23 and48 d, feed intake adjusted for BW, and feed efficiency. Average adjusted progenytrait values were calculated for G2 animals after adjusting phenotypicobservations on offspring for fixed effects, covariables, maternal geneticeffects, the additive genetic contribution of the mate, and heterogeneitybetween sexes and were used as dependent variable in the quantitative trait loci(QTL) analysis. A full sib interval mapping approach was applied using genotypesfrom 420 markers on 27 autosomal linkage groups. Four QTL exceeded significancethresholds. The most significant QTL was located on Chromosome 1 at 235 cM andhad a 4% genomewise significance for feed intake between 23 and 48 d.Furthermore, this QTL exceeded suggestive linkage for growth between 23 and 48 dand BW at 48 d. A second QTL was located on linkage group WAU26 at 16 cM andshowed suggestive linkage for feed intake between 23 and 48 d. On Chromosome 4,at 147 cM a third QTL, which had an effect on both feed intake traits, wasfound. Finally, a fourth QTL, which affected feed intake adjusted for BW, waslocated on Chromosome 2 at 41 cM.