Objective: To investigate the association of iron with stress hormones and insulin resistance in patients with gestational diabetes mellitus (GDM). Methods: Seventy-five pregnant women diagnosed as GDM during 24-28 weeks were collected from January to November 2015 in Yantai Yuhuangding Hospital, and 75 normal pregnant women were used as control group. Blood glucose, insulin, stress hormones and iron metabolism related indexes were detected. Homeostasis model assessment for insulin resistance (HOMA-IR) was used to evaluate insulin resistance, and the correlation of iron metabolism with stress hormones and insulin resistance was analyzed. Results: Compared with control group, norepinephrine (NE) and epinephrine (E) levels were higher in GDM group (both P<0.05), but there was no significant difference in cortisol level between two groups (P>0.05). Serum ferritin (SF), serum iron, and transferrin saturation levels were higher in GDM group than those in control group(all P<0.01). Multivariate logistic analysis showed that cortisol, E, and NE levels were positively correlated with SF level in GDM group (all P<0.05). Cortisol and E levels were positively correlated with transferrin saturation (both P<0.05). SF and transferrin saturation were positively correlated with HOMA-IR in two groups (P<0.05 or P<0.01). Conclusion Iron overload may involve in dysfunction of stress adaptation and insulin resistance in patients with GDM. (Chin J Endocrinol Metab, 2018, 34: 563-566)