Broiler chicks of different ages were used to study particle size disappearance and the effect of particle size on feed intake. The disappearance of particles larger than 1.18 mm was obvious at all ages. However, it was noticed that at 8 and 16 d disappearance of particles between > 1.18 mm and < 2.36 mm was most pronounced. As birds became older, disappearance rate was greatest for particles > 2.36 mm. Throughout a 24-h period, particle breakdown was noted. Birds did eat these smaller particles at the end of a 24-h period, especially when the concentration of large particles was reduced. Chemical analysis revealed that birds selected material on the basis of particle size, since nutrient composition of the diet and of different diet fractions did not change throughout the day. Changing particle size abruptly from crumbles to pellets did not adversely affect overall feed consumption (P > 0.05) or bird performance. Key words: Broiler, particle size preference, crumbles, pellets