Dissertation (MMED Obstetrics and Gynaecology)Predicting fetal macrosomia is an obstetric challenge and the management requires an experienced obstetrician. Women who deliver macrosomic babies have been observed to sustain adverse maternal and fetal outcomes such as postpartum hemorrhage which is the leading cause of maternal mortality. The prevalence of fetal macrosomia in developed countries is 15 - 20 % while in developing countries the prevalence ranges from 2% - 9 %. This study aimed at assessing risk factors for fetal macrosomia and maternal fetal outcomes among women attending Iringa regional referral hospital from June to December 2020 for delivery. An unmatched case-control study with 216 participants of whom 72 were cases - women who delivered babies weighing ≥ 4000g and 144 were controls - women who delivered babies weighing 2500 g to 3499g. A purposive sampling technique was employed to recruit both controls and cases. SPSS version 25 software program was used for data entry and analysis. Risk Factors for fetal macrosomia at Iringa Regional Referral hospital were advanced gestation age (AOR=8.10, 95% CI 3.66-17.91, p=<0.0001) and diabetes mellitus during pregnancy (AOR =14.94, 95% CI 1.60 -39.91, p= 0.0178). Maternal outcomes included prolonged labor 2.64 (95% CI, 1.45 – 4.80, p=0.0015), Cervical tear (p=0.0117), perineal tear 5.00 (95% CI, 1.48 – 16.85, p=0.0094) and postpartum hemorrhage (p=0.0117). Fetal outcomes included NICU admissions 3.311 (95% CI, 1.57 – 6.95, p=0.0016) and neonatal hypoglycemia (p=<0.0001). Although, were not statistically significant macrosomic babies experienced birth asphyxia 1.36 (95% CI, 0.67 – 2.75, p=0.3914) and neonatal death 2.04 (95% CI, 0.40 – 10.39, p=0.3890) as compared to non-macrosomic babies. Women with advanced gestational age and diabetes mellitus during pregnancy are at an increased risk of delivering a baby with macrosomia at Iringa Regional Referral Hospital. An early plan for the mode of deliverywill aid the prevention of advanced gestational age. Ensuring a healthy diet and physical exercises in our communities will help to reduce diabetes mellitus and hence fetal macrosomia.