BACKGROUND: Obesity and overweight are more common, especially among women of reproductive age. Therefore, the approach to maternal obesity requires a multidisciplinary approach, especially health professionals working in primary care preventive health services.AIM: The aim of the study is to determine the effect of maternal obesity on maternal and newborn health in Al Khansaa Teaching Hospial, City of Mosul, Iraq.MATERIALS AND METHODS: The study, which was planned as à case-control study, was conducted in the Al Khansa Teaching Hospital City of Mosul, Iraq.The inclusion criteria included women in postnatal period in the same Hospital, speaking and understanding Arabic, knowing her pre-pregnancy weight, not having any chronic disease (diabetes, hypertension, trioid diseases, etc.) before pregnancy, pre-pregnancy body mass index (BMI) 18.5–25, those with a BMI >29.9, and those with primary school or higher education were included. The exclusion criteria included multiple pregnancies, without any formal education, physical disability (that prevented the completion of the data collection forms), and mental health problems. Data were collected with the data collection form and Edinburgh Postpartum Depression Scale.RESULTS. The study was completed with 286 women, 142 cases and 144 control groups. There was no statistical difference between the case and control groups in terms of family type and employment status (p>0.050). While the mean age, pregnancy and number of living children of the women in the case group were statistically higher, their educational status was found to be lower (p<0.050). It was found that women with obesity experienced health problems such as urinary tract infection, anemia, gestational diabetes, psychological problems, and preeclampsia/gestational hypertension at a higher rate than women in the control group (p<0.010), and women in the control group gained 13.94±5.29 kg (p=0.001).CONCLUSION In conclusion, it was found that women in the case group experienced pregnancy, early and late postpartum complications at a higher rate than the control group, while there was no difference between the groups in terms of depression at the end of the sixth week postpartum.