Background: Maternal obesity is highly prevalent in Fiji and the perinatal and long-term consequences are likely to be significant. We investigated the relationship between maternal body mass index and maternal and neonatal outcomes and birth weight centiles in Fijian women. Aims: We sought to use the Intergrowth 21 st (IG21) standard to record the proportion of babies born over the 90 th centile and to examine the association of other maternal and neonatal outcomes with normal weight, overweight and obesity amongst women presenting for antenatal care at the Colonial War Memorial Hospital in Fiji. Methods: From January 2014 – December 2015 we undertook a prospective cohort study that used a structured questionnaire to collect data on women presenting for antenatal care. Body weight was recorded at the booking visit and adjusted to estimated pre-pregnancy bodyweight based on gestation at booking. Midwives collected follow up data regarding the outcomes of these pregnancies and we used the IG21 standard to estimate birthweight centiles. Results: Of the 1397 records, 79 women were underweight and were excluded for detailed analysis. For the remaining 1318 cases detailed pregnancy and follow-up data were available. Compared to normal weight women overweight women were older, parous and were more likely to have pregnancy-related hypertension and were more likely to have an induction of labour. A sixth (n=224;16.7%) of the babies were above the 90 th centile of birthweight according to IG21 standard and as maternal BMI class increased, the odds of the baby’s birthweight being > 90 th centile increased. Compared to normal weight women, women with class II or II obesity were three times more likely to have a baby over the 90 th centile (AOR 3.053; CI 1.907-4.889). Conclusions: A significant proportion of babies born in Fiji are large for gestational age which predisposes them to long term adverse metabolic health outcomes. Addressing maternal obesity before pregnancy is going to be key if Fiji is to curb the growing trend in child and adult obesity and metabolic disease in later life.