Introduction: Cutaneous leishmaniasis (CL) is a common protozoan disease in Iraq characterized by localized ulcers, primarily on exposed skin. This study aimed to investigate the hematological parameters of infected patients using a complete blood count (CBC) in the endemic area of Diyala Governorate, northeast of Baghdad. This has been studied in newly diagnosed, untreated individuals and patients receiving sodium antimony gluconate. Methodology: Hematological screening was performed on blood samples from 161 patients with microscopically diagnosed cutaneous leishmaniasis before and after treatment. Anti-Leishmania IgG was also assessed by ELISA in seropositive and seronegative subjects. Results: The newly diagnosed, untreated patients showed no significant differences in blood cell counts, whereas treated patients had significant changes in white blood cell composition, including absolute neutrophil count (ANC), absolute monocytes (MID), eosinophils Granulocytes and Neutrophil-Lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), platelets count (PLT) and Mean Platelets Volume (MPV), following the administration of five consecutive sodium stibogluconate injection. In addition, the anti-Leishmania IgG seroprevalence was highest (85%) in the newly diagnosed, untreated group and gradually decreased with continued treatment. However, there was no significant difference in red blood cell components including red blood cells (RBC), hematocrit test (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and red cell distribution width (RDW) before and after treatment. Conclusions: The current data gave an insight into certain hematological factors regarding WBC subtypes, along with cutaneous leishmaniasis treatment. In addition, the anti-Leishmania IgG may be considered a marker for therapeutic monitoring.