Cattle exclusion fencing has been recommended as a best management practice for the control of sediment, phosphorus, and nitrogen pollution in agricultural streams for several decades. The effectiveness of this practice for water quality improvement is varied. This review summarizes the findings of seventeen water quality studies where monitoring extended for up to 5 years. In general, cattle exclusion fencing decreased TSS and TP. The effect on dissolved forms of nutrients is more tenuous. Grazing cattle impact streams by damaging stream banks, kicking up streambed sediment, directly defecating into the water, and increasing polluted runoff risk in riparian areas. Improved study design and stream restoration practices may aid in increasing the understanding of the connection between riparian ecosystem recovery and water quality.