Introduction: The differentiation inhibitory factor [NM23] can inhibit the differentiation of murine and human myeloidleukemia cells, [NM23] genes play a role in the growth and differentiation of normal and malignant hematopoieticcells. A statistically significant correlation between the expression of [NM23-H1] was observed in ALL , a poorprognosis and a low percentage of complete remission were also associated with the [NM23-H1] expression level.Materials and methods: a peripheral blood sample from 25 newly diagnosed ALL cases and 10 control groupwere analysed for NM23-H1 mRNA expression level by real time PCR. Results: Nm23-H1 mRNA wasoverexpressed in ALL cases than for the control group with a mean level of 0.99 ± 0.74 ,0.305 ± 0299respectively, The resistant cases expressed a significantly higher NM23-H1 level (mean = 0.975) than thosewho achieved remission (mean=0.805). And dead cases expressed a highly significant level of the studiedgene (mean = 1.780). Conclusion: In our study there was highly significant positive correlation between thelevel of expression of NM23-H1 gene and the outcome of the patients P value 0.001.