In a self-aligning roller bearing providing an outer race, an inner race, a plurality of barrel-shaped rollers, and a pair of cages, guide surfaces formed on outward flange portions of the cages for guiding the barrel-shaped rollers are caused to come closer to ends of the barrel-shaped rollers, so that the barrel-shaped rollers can be guided without fail even if an axial load is received. Therefore, the barrel-shaped rollers are prevented from being skewed, from increasing in torque required for rotating the barrel-shaped rollers, and from seizing up the barrel-shaped rollers.