Background: the assessment of peripheral blood blast count, some hematological parameters in acuternleukemia is not researched well in developing countries although, nowadays leukemia is the main concernrnin these countries. rnObjective: to assess the value of peripheral blood blast count, selected hematological parameters beforernand during chemotherapy of acute leukemia patients at Tikur Anbessa specialized hospital (TASH), AddisrnAbaba, Ethiopia. rnMethods: A prospective cohort study was conducted in acute leukemia patients at Tikur AnbessarnSpecialized Hospital from February to December 2020to assess the change in selected hematologicalrnparameters at three different times after taking first induction treatment. Complete blood cell count (CBC)rnand peripheral blood morphology of those patients were investigated in three different time points whichrnstarts in initial diagnosis, next at 7 and 14 days of induction treatment. Bone marrow analysis data extractedrnfrom pathology department at the beginning of patient diagnosis. Data were entered and analyzed usingrnSPSS version 23. Descriptive statistics were used to describe socio-demographic factors, chi square test ofrnassociation was run for categorical variables and paired t-test and ANOVA was also used to compare prernand during induction blast counts and selected hematological parameters. P values less than 0.05 was usedrnto declare statistical significance. rnResult: 30 newly diagnosed acute leukemia patients aged 2 to 69 years were enrolled in this investigation.rnIn this study age group is related with that of leukemia type. Some of the hematological parameters arernassessed during the three time period. White blood cell (WBC), Blast count, Platelet, but not the otherrnhematologic parameters before the administration of chemotherapy are statistically different with thosernvalues of day 7 and day 14 after starting chemotherapy. However, the two parameters WBC (50700, 5200,rn2180 cells/ul) and Blast cell count (29700, 3150, 150cells/ ul) at the three time points show a significantrneffect for time. The respective values for Platelets were 92700, 37100, 55900 cells/ul. rnConclusion: blast count and WBC which was counted (mean Â± SD) at day 7 and 14 of induction treatmentrnhas a significant value to assess the response of the patient by the treatment. Therefore it should be used asrna surrogate marker in the course of induction treatment. In contrast other hematological parameters did notrnshow an effect on the response of the patient by the treatment. Analysis of larger sample size with otherrnadditional tests like immunological, biochemical, cytogenetic and flowcytometry should be done on thisrnarea of study.