A vehicle body frame structure of a straddle-type vehicle (100) comprises a head pipe (2) into which a steering shaft (105) connected to a handle (121) is inserted; and a pair of main frames (3) extending rearward and outward in a vehicle width direction from the head pipe (2) in such a manner that the main frames are spaced apart from each other in the vehicle width direction. Each of the main frames (3) includes an upper frame (11) extending rearward from an upper portion of the head pipe (2), and a lower frame (12) extending rearward from a lower portion of the head pipe (2). Between the upper frame (11) and the lower frame (12), a retraction space (53) which is located inward in the vehicle width direction relative to an end portion of the handle (121) in a turn operation state is provided.