A hydrodynamic type oil-impregnated sintered bearing includes a porous bearing body of sintered metal having a bearing surface in which hydrodynamic pressure generating grooves slating against an axial direction are provided. Lubricating oil or the base oil of lubricating grease to be impregnated into the bearing body is selected from among (a) mixtures of poly-α-olefin or hydrogenated compound thereof and ester and (b) ester. The ester is preferably polyol ester. In the cases of the lubricating grease, the thickener of the lubricating grease is preferably composed of urea compound. A plurality of bearing surfaces may be formed on the inner periphery of the bearing body so as to be separated from one another. The hydrodynamic type oil-impregnated sintered bearing may be suitably applied to a spindle motor for information equipment.