Research Article published by Int. J. Environmental Engineering, Vol. 7, No. 2, 2015Water reuse is one of the potential ways to complement the existing portable water sources. Its adoption is becoming of interest due to water shortages in many parts of the world. Its implementation is supported by several benefits though it has challenges as well. This paper provides a review of practice of the water reuse for irrigation in the world and focuses on its potentiality in Tanzania with a highlight on the water supply and wastewater treatment situation in the country. The challenges that need to be addressed, the benefits expected and global wastewater treatment options, capital and operation costs as well as the cost benefit analysis have been pointed out. Some arguments to justify a shift to water reuse in irrigation has been given. Lastly, it has been shown that full implementation of water reuse will require among other things, proper defined policy and institutional framework, clear guidelines as well as more research and investment on wastewater treatment.