Background:Malaria is aninfectious parasitic disease caused by protozoa of the genus Plasmodium. Among these,Plasmodium falciparum and Plasmodium vivax are the most common species infecting humans. These species causevarious hematological abnormalities, including anemia, thrombocytopenia, and leukopenia. However, evidenceon the prevalence and determinants of these abnormalities between these speciesremains limited and inconsistent among malaria patients in Bahir Dar city. Objectives: To assess hematological abnormalities and theirdeterminantsamong patients infectedwithPlasmodium falciparum and Plasmodium vivaxin Bahir Dar City. Methods and Materials:An institution-based comparative cross-sectional study was conductedfrom February 3 to April 10, 2026.Venous blood samples were collected from participantsconfirmedto have Plasmodium falciparum or Plasmodiumvivax infectionfor complete blood count(CBC) analysis.Data were cleaned, coded, and entered into statistical package for social science version 25.The Chi-square test was used to assess associations between categorical variables. An independent samples t-test was used to compare means of continuous variables. Binary logistic regression was used to identify determinants of hematological abnormalities. A p-value< 0.05 wasconsideredstatisticallysignificant. Results: Among 462 participants, 231 were infected with Plasmodium falciparum and 231 with Plasmodium vivax. The majority of participants were male, 253 (54.8%). The most encountered hematological abnormality was thrombocytopenia (57.36%), followed by anemia (31.39%). Thrombocytopenia and anemiawere significantly higher among participants infected with Plasmodium falciparum than those with Plasmodium vivax, with AORs of 1.895(CI: 1.243–2.887) and 3.476(CI: 1.838–6.574), respectively. Previous malaria infection wassignificantly associated with thrombocytopenia (AOR = 1.788, CI: 1.037–3.082). Conclusion:Hematological abnormalities were common among malaria-infected patients, with higher occurrence in Plasmodiumfalciparum than Plasmodium vivax.Several determinants were associated with these abnormalities. Therefore, routine hematological assessment, early species-specific diagnosis, and swift treatmentare recommended to improve patient outcomes