A review of the various methods used for modeling nuclear steam generators is presented in this report. The review includes mathematical models, numerical techniques, empirical correlations for two-phase flow, and relevant design and performance data for steam generators. Applicability of the existing thermal-hydraulic codes for simulating transient performance of steam generators is also discussed. Based on our review, we note that, for detailed steam generator modeling, distributed parameter models based on finite-difference formulations appear to offer advantages over the control volume approaches. It is suggested that evaluation of heat transfer correlations for steam generator modeling should be based on actual steam generator simulations. Desirability of additional experimental data, especially for U-tube steam generators, is also indicated.