This paper presents a state-of-the-art review of two-phase flow and flow boiling across horizontal tube bundles. The review covers studies related to the dynamic aspects of two-phase flow on the shell side of staggered and in-line tube bundles for upward, downward, and side-to-side flows (i.e. the evaluation of void fraction, two-phase flow behaviors and pressure drops). Heat transfer experimental work and heat transfer prediction methods on tube bundles in cross-flow for plain, low-fin, and enhanced boiling tubes are also covered. The proposed flow pattern maps and semi-empirical correlations for predicting void fraction and frictional pressure drop are critically described. These prediction methods are generally based on experimental results for adiabatic air-water flows, and noticeable discrepancies are revealed in the results provided by them. This study reveals that before now, there were no heat transfer prediction methods that can be recommended as a general design tool. Finally, this study suggests further research focusing on the development of representative databanks and prediction methods.