Methaemoglobin (Met-Hb) is a type of the oxygen-carrying metalloproteinhemoglobin. The heme group iron exists as ferric (Fe3+) iron, rather than the ferrous (Fe2+) iron of typical hemoglobin. Met-Hb is unable to perform the function of binding to oxygen like oxyhaemoglobin does. The aim of this study was to compare methaemoglobin levels between AA and AS haemoglobin variants among the Ijaw, Igbo and Yoruba ethnic groups residing in Bayelsa State, Nigeria. A total of 150 subjects were enrolled for the study. One hundred and sixteen subjects constituted the Ijaws; 21 Igbos and 13 Yorubas. For each subject, 4mls of blood sample collected in EDTA bottle was assayed for methaemoglobin using a spectrophotometric method. Results revealed there was no significant difference in the methaemoglobin mean levels between the AA and AS haemoglobin variants (P-value>0.05) of the ethnic groups except the Igbo ethnic group (P-value <0.05). However, comparing the methaemoglobin mean levels among the ethnic groups showed a significant mean difference of methaemoglobin (P-value 0.05). In conclusion, this study has revealed that methaemoglobin levels changes significantly based on studied tribes but does not change based on studied haemoglobin variants.