This article represents a comparative study on the fish fauna from the Bistricioara River before the anthropic impact that took place after 1960 and the present fauna. The evaluation of the present status of the fish communities was performed in 4 collecting points on the main course of the river, by highlighting the abundance and absolute biomass, the numeric stock and gravimetrical stock at each collecting point. The ecological rang of every species in the structure of fish communities and the present zoning fish of the river were determined by calculating the ecological indices (constancy, dominance, ecological significance). The biodiversity index and the biological integrity index (IBI), which are the best indicators of the degree to which the fish fauna is affected by the anthropic impact, were also calculated.