Glucose-dependent insulin secretion (GDIS), reactive oxygen species (ROS) production, and oxidative stress in pancreatic β-cells may be tightly linked processes. Here we suggest that the same pathways used in the activation of GDIS (increased glycolytic flux, ATP-to-ADP ratio, and intracellular Ca²⁺ concentration) can dramatically enhance ROS production and manifestations of oxidative stress and, possibly, apoptosis. The increase in ROS production and oxidative stress produced by GDIS activation itself suggests a dual role for metabolic insulin secretagogues, as an initial sharp increase in insulin secretion rate can be accompanied by progressive β-cell injury. We propose that therapeutic strategies targeting enhancement of GDIS should be carefully considered in light of possible loss of β-cell function and mass.