In a multi-piece solid golf ball wherein a solid core of a multilayer structure including an innermost core and at least one intermediate layer enclosing the innermost core is surrounded by a cover, the golf ball has a specific gravity of 1.0-1.1 g/cm.sup.3 and a distortion A of 2.5-4.0 mm under a load of 100 kg, the innermost core has a distortion B of 3.0-6.0 mm under a load of 100 kg, wherein 1.2.ltoreq.B/A.ltoreq.1.7, and the cover has a greater hardness than the hardness of the innermost core. The ball will follow an appropriate high trajectory when hit by those golf players with a head speed of less than 40 m/sec. The ball is improved in flying performance, flying distance, feeling, impact, and durability.