Anaemia in pregnancy is a major health problem affecting 36.5% of pregnant women globally. The occurrences of anaemia in pregnancy in the Sultanate of Oman is still high despite of the several strategies put in place. Anaemia in pregnancy is associated with adverse maternal-fetal outcome that increases maternal and neonatal morbidity and mortality rates. However, the association is barely known in Oman. A better understanding of the association would give new ideas on how to improve current guidelines on screening, treatment and prevention of anaemia in pregnancy. The purpose of this study was to explore the relation between anaemia in pregnancy and adverse maternal-fetal outcomes. The study also explored the risk factors related to anaemia in pregnancy in Oman. A quantitative retrospective comparison study design was used. Medical records of women who attended antenatal care and gave birth at Sultan Qaboos University hospital between 1 st/01/2020 to 31st/12/2022 were examined. The sample size was calculated using Epi Info statistical software version 7.2.5.0. Convenient sampling method together with inclusion and exclusion criteria were used to select eligible women. Women in Oman reproductive age 15 and 49 years, with singleton pregnancy, a record of third trimester haemoglobin were included in the study. Women were excluded if their first visit was at time of giving birth, had acute, chronic, hereditary and gestational diseases. Lastly, if the foetus were diagnosed with congenital abnormalities. The study included 454 women with anaemia (Hb 11.0 g/dL) who were compared with 269 women without anaemia (Hb > 11.0 g/dL). Data was recorded using data collection sheet and analysed with Statistical Package for the Social Sciences. The relationship was assessed using the Mann-Whitney U test and Chi-square test with set P value ≤ .05. A total of 723 pregnant women who attended antenatal and delivered at Sultan Qaboos University Hospital met the eligibility criteria and were included in the study. Of these, 445(62.8%) were anaemic and 269(37.2%) were non-anaemic. The risk factors that were found to be statistically significant included; body mass index P ≤ .041, nationality p ≤ .030, and weeks of gestation P ≤ .037. Nevertheless, parity, gravidity, antenatal visits, place of residence occupation showed no statistical significance. In addition, anaemia in pregnancy was significantly associated with adverse maternal-fetal outcomes like postpartum haemorrhage with p ≤ .019, preterm birth with P ≤ .037, low birth weight with P ≤ .009, intrauterine growth restriction with P ≤ .002. However, LOS and CS were not statistically significant. The results indicated that anaemia continues to be a severe health problem among pregnant women in Oman. Anaemia in pregnancy was associated with adverse maternal-fetal outcomes and risk factors and it increases maternal and neonatal morbidity and mortality rates. Early screening of pregnant women, routine provision of standard dose of iron supplements, routine nutritional education, proper treatment of anaemia with doubled effort in third stage of labour, would reduce the occurrences of anaemia and its consequences.