 Regionalization techniques have become increasingly important in the field of hydrology as they allow for the prediction of streamflow in ungaged catchments. Two main approaches exist, one which estimates parameters of streamflow statistics, such as flood quantiles, and another which uses a rainfall runoff model to simulate continuous streamflow or estimate continuous streamflow without using a model. Most methods used to estimate continuous streamflow for ungaged catchments can also be applied to estimating streamflow statistics. This paper reviews both distance-based and regression-based methods, discussing their advantages and disadvantages. This article was authored by Waihi, Abardisi, and Ez.