A medical survey was conducted on a group of 209 patients investigated in 2020. Laboratory determinations and analyses have been performed in the New Central Med Lab (Bacău). In this study, the purpose was to monitor the distribution of investigated patients by normal values of WBCs versus the subjects with WBCs alterations, either leukopenia, or leukocytosis, detect certain types of leukemia, the distribution of subjects by gender, age, urban/rural environment. Thereby, tests for a quantitative and qualitative assessment of hematological parameters were performed: complete blood count, cytological blood smear analysis, hemoleucogram. The blood smear cytologic examination is a valuable observation, that is prior in the diagnosis of hematological disorders. The blood smears were fixed and stained May Grünwald – Giemsa.