Thirty-two Yorkshire Landrace x Duroc castrated male and female pigs with a live weight of approximately 14.6 kg were used to study the effect of maize meal substitution by Jerusalem artichokes 0, 33, 66 and 100% (on dry matter basis) in the ration for pigs aged from 61 to 96 days. The pigs were individually allocated to cages and distributed in a random block design with 4 treatments and 8 replications. Fresh Jerusalem artichokes were offered to the animals. Daily feed intake (kg DM/day), weight gain (g/day) and feed conversion (kg DM/kg gain) in increased maize substitution order were: 1.26, 1.22, 1.18 and 1.05; 483, 480, 403 and 283; 2.61, 2.54, 2.93 and 3.71. There were significant differences (P<0.01) between diets containing the highest maize substitution levels (66 and 100%) and the others, probably due to the bulking characteristics and digestion pattern of the tubers.