Methemoglobinemia (MetHb) is a well-known but frequently forgotten cause of hypoxia and respiratory distress in patients of all ages. MetHb is an oxidized form of hemoglobin with iron in the ferric form instead of the usual ferrous form, which results in decreased availability of oxygen to the tissues and increased oxygen affinity resulting in cyanosis and tissue hypoxia. MetHb occurs when red blood cells contain MetHb higher than 1%. Clinical features are proportional to the concentration of the MetHb, which range from asymptomatic state to seizures and cardiac arrthymia to fatality. Congenital MetHb is a rare genetic abnormality in which patient is asymptomatic and presents with cyanosis which may be present since birth. During pregnancy, it may lead to uteroplacental insufficiency causing intrauterine growth retardation, oligohydramnios, severe preeclampsia and abruption. The clinical features and long-term outcome are poorly documented and there are no systematic reviews. There are very few clinical papers and case reports published on literature with regards to this. We report a case of a pregnant woman who presented to us at 25 weeks of gestation with cyanosis and dyspnea and she was diagnosed as MetHb in pregnancy. The management of this patient involves multidiscipline team including obstetrician, haematologist, anaesthetist and paediatrician. She was monitored closely during pregnancy and the most critical period is during labour. Patient was monitored clinically for cyanosis and a serial of arterial blood gas (ABG) and MetHb level was monitored during labour. The purpose of this case report is to share the management of MetHb in pregnancy and the outcome of the pregnancy in a woman with MetHb.