Objective: Substantial evidence indicates that polydextrose (PDX), a soluble fiber, alters glucose metabolism and reduces the glycemic response when acting as a replacement for sugars. These effects are accompanied by a significant decline in insulin. This is the first study to assess the effects of PDX on glycemia and insulinemia in women only. Methods: The study was acute, randomized, double-blinded and crossover in design in order to assess the effects of a breakfast containing 12.5 g of PDX (1600 kJ) versus an isocaloric control breakfast on glycemic and insulinemic responses in 32 women (27.4 ± 6.6 yrs; 25.9 ± 2.7 kg/m²). The levels of blood glucose and blood insulin were assessed before (-10 min), and 30, 60, 90, 150 and 240 min after breakfast. Glucose was measured using an enzymatic method (Gluco-quant Glucose/HK, Roche Diagnostics), and insulin was measured by ELISA (E170 Module, Roche Diagnostics). All results were expressed as iAUC and analyzed using a mixed model in SAS. Results: The mean iAUC of blood glucose for the breakfast containing PDX was higher than the control breakfast (P = 0.06; 99 ± 140 mmol.L-1.min and 41 ± 122 mmol.L-1.min, respectively). The mean iAUC of blood insulin for the breakfast containing PDX was significantly lower than the control breakfast (P = 0.04; 4851 ± 3185 mU.L-1.min and 5756 ± 3622 mU.L-1.min, respectively). Conclusion: In our study, the glycemic response of PDX was similar to control during the first hour after breakfast and increased after but not significantly. Our trial is the first to report a delay in glucose absorption during the postabsorptive phase due to the consumption of PDX at breakfast time. The effect of PDX in delaying glucose absorption might help prevent weight gain and the development of type 2 diabetes. PDX significantly reduced the levels of insulin in women, as expected.