Re-emergence of infectious diseases are commonly seen with viral infections among which those caused by Influenza viruses are by nature unstable and unpredictable because of the unique capability of changing their antigenic characteristics by mutation. This study aims to unravel the haematological consequences of Influenza A H1N1 infections and also to compare it with Influenza A H1N1 negative infections. Materials and Methods: Applying the relevant inclusion and exclusion criterion yielded a total hundred patients consisting of sixty-five Influenza A H1N1 positive and thirty-five Influenza A H1N1 negative patients. The CBC profile of all these subjects were obtained from an Automated hematology analyzer which yielded various haematological parameters. Results: The mean hemoglobin was 12.145 gm/dl in H1N1 positive cases and 12.6 gm/dl in H1N1 negative cases. The mean hematocrit value was 36.28% in H1N1 positive cases and 40.65% in H1N1 negative cases. 26 H1N1 positive cases had leucopenia, whereas 4 H1N1 negative cases had leucopenia and 8 H1N1 positive cases had leucocytosis. Lymphopenia was observed in 60% of H1N1 positive cases and in 22.9% H1N1 negative cases. Thrombocytopenia was a feature in 8 H1N1 positive cases and 2 H1N1 negative cases. Conclusions: Several haematological variations are observed in both H1N1 positive cases and H1N1 negative influenza cases, but to different extents.