Barley, rice, maize and peas as starch sources were tested to study if differences in glycemic index may affect feed utilization, productive performances and quality traits for growing pigs. Four experimental diets were formulated to include 420g starch/kg, provided by barley, barley/broken rice, barley/maize or barley/peas combinations (diets coded B, R, M and P, respectively). A 45% of total starch from diets R, M and P was provided by broken rice, maize or peas. The in vitro characterization of feeds showed that the rapidly digestible starch fraction was highest for R (P<0.001) and no differences were recorded among the other diets, whereas the slowly digestible fraction was higher for B and M than for R (P<0.01) and that higher than for P (P<0.01). Then the resistant starch fraction was higher for P than for B and M (P<0.001) and those higher than for R (P<0.001). The rate of glucose release was fastest with R (P<0.001), and estimations of glycemic index were highest for R and lowest for P (P<0.001). For the in vivo trial, a total of 72 Duroc×(Landrace×Large White) crossbred gilts, with 63.0±4.55kg body weight (116±3days of age) was used. Statistical trends (P model<0.10) were observed for ADG and FCR; gilts fed diet P grew faster (P<0.05) and had a lower FCR (P<0.05) than those fed diet R. The apparent organic matter digestibility for diets R and P was lower than for diet B (P<0.001) but higher than for diet M (P<0.01). Similarly, the apparent crude protein digestibility was higher with diet R than with diet M (P<0.01). Gilts consumed from 32% to 40% of available feed within the first 2h after offering, then the rate dropped from 2 to 4h (P<0.05) and was virtually nil from 10 to 12h for all diets. There was a limited influence of diet on carcass and meat characteristics but the intramuscular fat from pigs fed B showed higher (P<0.001) total saturated fatty acids and lower (P<0.001) total monounsaturated fatty acid contents than that from pigs fed M. It can be concluded that the pattern of gut digestion of the starch source may affect backfat thickness and growth performance of gilts, with scant effect on meat quality.