Background: Omentin-1 an adipokine expressed in visceral fat, endothelium and gut. Its level was found lower in obesity and type II diabetes. It is expressed in placenta and was associated with insulin sensitivity during pregnancy. Methods: Rats were divided into 4 groups; group I: control, group II: sham group (normal pregnant), group III: gestational diabetic group and group IV: omentin-1 treated gestational diabetic group. Blood glucose, insulin HOMA-IR, lipid profile, CRP and osteopontin (OPN) levels were measured and gene expression of PI3K, AKT, GSK-3, NF-κB and OPN. Results: In group III, a significant increase in insulin resistance, CRP, OPN, increased mRNA expression of GSK-3, NF-κB, and OPN while PI3K and AKT expression decreased. Omentin-1 treatment in group IV attenuated insulin resistance, increased PI3K and AKT expression but decreased OPN, GSK-3, and NF-κB expression. Conclusion: Omentin-1 administration in gestational diabetic rats improved insulin sensitivity and attenuated inflammatory response through PI3K/AKT/GSK-3 pathway. Keywords: omentin-1, osteopontin, gestational diabetes, PI3K