Targeted radiation therapy, or radioimmunotherapy, has been an important recent advancement in the treatment of patients with B-cell non-Hodgkin's lymphoma (NHL). 90Y ibritumomab tiuxetan comprises the murine monoclonal antibody ibritumomab, the linker chelator tiuxetan and the radiolabeled isotope 90yttrium. 90Y ibritumomab tiuxetan has been demonstrated to be efficacious in the treatment of B-cell NHL. Initial Phase I/II trials established the therapeutic dose of ibritumomab tiuxetan for low-grade NHL to be 0.4 mCi/kg, or 0.3 mCi/kg for patients with mild thrombocytopenia. Currently, there are many ongoing trials of ibritumomab tiuxetan with different dose schedules and intensities, in combination with chemotherapy and with stem cell transplantation, in an attempt to improve response rate and duration and to study its effectiveness in other B-cell lymphomas, including diffuse large B-cell lymphoma and mantle cell lymphoma. Radioimmunotherapy has great promise and the safe incorporation of 90Y ibritumomab tiuxetan into treatment will hopefully result in improved survival for patients with NHL.