The aim of the present study was to investigate in situ- expression of different markers related to T cell population Th1 (STAT4), Th2 (GATA3), Treg.(FOXP3) and T cytotoxic (CD8) in Egyptian patients suffering from chronic complicated schistosomiasis haematobium infection, using real time quantitative photocytometric analysis. On the other hand, to spot on the dominating T cell upon which the subsequent events had been built. Due to ethical consideration, the present work was applied only on tissue biopsies of the selected cases after cystectomy. Therefore, the existing research was built-in 29 schistosomiasis patients complicated with bladder cance. Cases in the present study were exposed to more or less continuous stimulation of Schistosoma egg antigen, either due to lack of treatment, failure of treatment or repeated exposure to infection. The cases in the current work were reported to be poorly controlled by unbalanced Th1/Th2 in which Th2 was dominated as proved by the significant higher expression level of GATA3 (Th2 marker) over STAT4 (Th1marker). In attempt to regain the control, Treg. (FOXP3) level was increased significantly, however, failed to dowen-regulate Th2(GATA3) which continue to expand resulting in more down-regulation of Th1 (STAT4). Instead, the relation between Th1 (STAT4) and T cytotoxic (CD8) was forcibly limited by the high expression level of Treg. (FOXP3) resulting in loss of their power in defending the host against both parasite and carcinogenic changes. These correlations give more clarification for the immune evasion process played by the parasite and tumor cells under the supervision of Tregulatory cells. In addition to the critical role of FOXP3 in manipulating STAT4 and CD8 in favor of malignant progression.