The results of the studies on air-water two-phase mixture flow in pipe bends connecting straight-axial horizontal sections of pipeline have been presented in the paper. In particular, the investigations concerned flow in bends, with the diameter of inner tube of 25 mm, the radius of its curvature of 75 mm and with the angle of obtuse of pipe bend of 180 degrees. One of the results of examinations was to determine flow patterns formed in bends. A method for calculation of friction factors of two-phase mixture flowing in bend was also presented. An attempt was made to describe quantitatively the variations in void friction of particular phases with regard to gas-liquid two-phase flow in straight-axial tubes.