Although computer models are now common tools for prediction of salinity intrusion in estuaries, many estuary managers tend to use simple and reliable tools such as empirical models. These models can be used as a fast instrument to determine the salt intrusion length as a function of directly measurable parameters. The aim of this study was to compare the empirical models performance with that of computer models. To achieve this, performance of a computer model and some empirical ones are evaluated for prediction of salinity intrusion in the Bahmanshir estuary. Field data were used for calibration and verification of the computer model. Using the verified model, different scenarios were considered to determine the optimal riverine flow under different conditions. Finally, the salinity intrusion in Bahmanshir was studied by empirical models to find the suitable model for prediction of the salinity intrusion length. Comparison of the obtained results indicated that the model of Van der Burgh (1972) is the most suitable empirical model for prediction of the salinity intrusion length in the Bahmanshir estuary.