Background: To study methaemoglobin content and NADH-methaemoglobin reductase activity of three human erythrocyte genotypes (HbAA, HbAS and HbSS).

Materials and Methods: Studies to ascertain methaemoglobin concentration and level of NADH-methaemoglobin reductase activity of three human erythrocyte genotypes (HbAA, HbAS and HbSS) were carried out in forty-three (43) healthy male participants of confirmed erythrocyte genotypes: HbAA (N=15), HbAS (N=15) and HbSS (N=13). Spectrophotometric method was used for determination of the two erythrocyte parameters.

Results: Whereas methaemoglobin concentrations in the three erythrocyte genotypes was in the order: HbASp>0.05) in methaemoglobin concentration and NADH-methaemoglobin reductase activity between HbAA and HbAS erythrocytes.

Conclusion: The results showed a relationship between erythrocyte NADH-methaemoglobin reductase activity and methaemoglobin concentration.