Steel wire ropes are used in elevators, cranes, mine hoistings, bridges, offshore and aerial ropeway systems. In this study, bending over sheave (BoS) fatigue lifetimes of 6 x 36 Warrington-Seale steel wire ropes have been determined theoretically and experimentally. Experimental findings have critical importance in identifying behavior of wire rope subjected to bending over sheave fatigue. Experimental studies have been performed to show effects of tensile load and sheave diameter parameters on BoS fatigue lifetimes of 6 x 36 Warrington-Seale steel wire ropes. Besides, a multiple linear regression model has been devised and novel theoretical BoS fatigue life prediction equation has been presented by using the least square method. The results indicate that there is a powerful correlation between the results obtained by theoretical model and experimental data. The BoS fatigue lifetime results can be used in the range of specific tensile loads investigated and diameter ratios used with acceptable error.