The U-bend has a significant influence on two-phase heat transfer and pressure drop as a result of the secondary flow which causes interactions between the liquid and vapour phases. Hence, in this study, the heat transfer and frictional pressure drop in the two-phase flow boiling evaporation of R134a in the elliptical U-bend tube heat exchanger evaporator with different eccentricities were investigated for downward flow orientation. The eccentricities of the elliptical cross-section range from 0 to 0.904 with the same hydraulic diameter of 8 mm being utilized. The numerical computations were implemented using computational fluid dynamics code for the operating parameters for the mass fluxes of 100 kg/m²s and 200 kg/m²s for the inlet vapour quality of 20%. A constant uniform heat flux of 10 kW/m² was imposed on the outer surface of the tube. For volume fraction tracking of each of the phases along the tube, the volume of fluid multiphase model coupled with the phase change model was utilized. The numerical calculations were validated and found to be consistent with what has been published in the open literature The results reveal that as the eccentricity of the elliptical U-bend tube increases, the heat transfer coefficient increases while the frictional pressure drop decreases. The bend was discovered to have a significant impact on the flow structures because the flow regimes upstream before the bend differed from the flow regimes downstream after the bend.