Gestational diabetes mellitus (GDM) is one of the most common medical pregnancy complications, leading to significant adverse maternal and neonatal outcomes. This study aimed to evaluate the effect of the implementation of health education on maternal and neonatal outcomes among women with GDM. A quantitative quasi-experimental convenience sampling was used to collect data on 140 pregnant women diagnosed with GDM who attended Sulaimani Maternity Teaching Hospital from November 1, 2021, to October 1, 2022. Data questionnaires were used to collect these data by direct interview. The mean ages of the intervention and control groups were 32.5±5.6 and 32.0±5.8 years, respectively. Most participants in both groups graduated from primary and secondary school (34.3% and 38.6%, respectively), received metformin for GDM management (61.4% and 62.9%, respectively), and most of them delivered by cesarean section (65.7% and 87.1%, respectively). Most women in the intervention group (82.9%) had no complications during labour compared to those in the control group (71.4%). The most frequent neonatal complications found in the control group were hyperbilirubinemia (34.3%), respiratory distress syndrome (30.0%), and heart disease (5.7%). Regarding the level of knowledge of GDM, there was a significant difference between the intervention and control groups (p=0.001). Participation in a health education program designed for women with GDM improved knowledge of the disease and increased awareness of how women can reduce its complications.