Objective: Children suffer from ALL (Acute Lymphoblastic Leukemia) a malignant tumour most commonly in underdeveloped countries all over the world. Various significant abbreviations of chromosomes which include translocations and also result in the fusion gene production are also in fashion (TEL-AML1, BCR-ABL and MLL-AF4). In the mentioned abbreviations fusion gene (TEL-AML1) has an association with cases of ALL. It also possesses prognostic and clinical importance. We aimed to detect fusion oncogene (TEL-AML1) frequency in the cases of ALL and its correlation to factors such as WBC, FAB subtype and age. Materials and Methods: We studied 66 ALL patients at Mayo Hospital, Lahore from August 2016 to June 2017. We did not include any case of T-ALL and on chemotherapy. We analyzed data on SPSS software and assessed prognostic features such as sex, age, level of haemoglobin, platelet count, immune-phenotype, WBC profile and FAB type . We performed an RT-PCR procedure and RNA extraction in order to detect any possible fusion oncogene (TEL-AML1). Results: In the total sample of sixty-six patients, fusion oncogene (TEL-AML1) frequency found in five patients (7.6%). About every case of positive (TEL-AML1) carried B-Lineage immune-phenotype, FAB ALL-L1, mean haemoglobin level (6 g/dl) and age (3-5) years. These parameters had a good relationship with the prognosis procedure. Conclusion: Fusion gene (TEL-AML1 ) frequency was about 7.6% in the research subjects which is not comparable with Western studies. In case of its universal acceptance, the fusion gene (TEL-AML1) identification in cases of ALL is likely to improve the satisfaction of the risk in order to shortlist a suitable therapy.