Background Gestational diabetes mellitus is the most common metabolic dysfunction that arises during pregnancy. GDM can lead to serious health complications for both the mother during pregnancy and after the delivery of the baby. Additionally, mother–offspring suffers from abnormalities in metabolism. The study aimed to investigate glutathione S‑transferase P1 and ghrelin genetic variants in pregnant women diagnosed with gestational diabetes using a tetra-primer amplification refractory mutation system. Results This study demonstrated that the frequencies of genotypes in women with GDM were GSTP1-AG (87.1%) and GHRL-GG (100%). The study revealed no significant differences in the frequency of either genotype or allele of both GSTP1 and ghrelin between GDM and healthy pregnant women. Conclusions This study may be the first study designed to demonstrate that there is no association between the genotype and allele frequencies of GSTP1 (rs1695) and ghrelin (rs696217) in the development of gestational diabetes mellitus in Egyptian women.