Background: While it is customary to apply the same haematological reference ranges, variations exist between populations. This study was conducted to determine hematologic profiles among a local population of north-western Tanzania.

Methods: This was a cross sectional study, which enrolled healthy adult blood donors in Mwanza, Tanzania. Collected blood samples were put in EDTA -coated tubes and haematological indices were determined using Auto Hematology-Analyzer. Results are summarized in medians plus 95% interquartile ranges and compared using either Mann–Whitney U or Kruskal–Wallis tests depending on appropriateness.

Results: A total of 163 (143 males and 20 females) adult healthy blood donors (median age= 31 years) were enrolled. We found a median haemoglobin level of 15.1 g/dL [10.5-23.8], erythrocytes of 5.3x10⁶/µL [4.1-8.3 x10⁶], haematocrit of 44.0 % [32.4-71.4], total leucocytes of 4300 cells/μL [1700-8500], lymphocytes 1700/μL [800-3000], neutrophils 2100/μL [300-5300]; mid-sized cells (monocytes, eosinophils and basophils) of 400/μL [100-1400] and platelets of 194x10³/μL [55.2-379.0 x10³]. We observed significantly higher haemoglobin level ( P = 0.017) as well as erythrocytes ( P = 0.012) and haematocrit (p = 0.006) among males than females.

Conclusion: The percentile range (2.5%-97.5%) which can be used to determine the higher and lower values of haematological profile normal ranges for most indices differ from Western adopted reference values. Therefore, we recommend a large study to establish local normal hematologic reference values.