Non muscle invasive bladder cancer is a heterogenous group. In non-muscle invasive bladder cancer, approximately 70%of patients presents as Ta. The majority of Ta tumors are low grade. High grade Ta urothelial carcinomas are rare tumors and have higher risk of progression than low grade Ta tumors. The literature is limited which associated with High grade Ta bladder cancer. In this paper, diagnosis, prognosis, molecular markers and treatments of high grade Ta urothelial cancers were reviewed.