We aimed to evaluate insulin secretion and insulin sensitivity in adults born preterm and their children. Subjects were adults born both preterm and at term, with their children aged 5-10 years born at term. Insulin sensitivity and secretion were assessed using hyperglycemic clamps in adults and frequently sampled intravenous glucose tolerance tests using Bergman minimal model in children. In total, 52 adults aged 34-38 years participated (31 born preterm, mean gestational age 33.3 weeks). Adults born preterm were less insulin sensitive than those born at term (19.0 ± 2.5 vs. 36.3 ± 5.2 mg · kg(-1) · min(-1)mU · L; P < 0.05) with compensatory increased first-phase insulin secretion (56.1 ± 8.5 vs. 25.3 ± 3.7 mU/L; P < 0.001) but similar disposition index indicating appropriate insulin secretion. These differences were independent of sex and remained when subjects born <32 weeks' gestation were excluded from analyses. In total, 61 children were studied (37 of preterm parents, mean age 7.9 ± 0.3 years). Children of parents born preterm had similar insulin sensitivity to children of parents born at term, but a correlation between parental and offspring insulin sensitivity was noted only among children of parents born preterm. In conclusion, adults born preterm have insulin resistance in midadulthood, but this was not associated with insulin resistance in their children.