There is provided a refrigerating machine oil composition comprising a base oil containing a polyvinyl ether and/or a polyoxyalkylene glycol derivative as a main component and having a kinematic viscosity of 1 to 8 mm2/s as measured at 40° C. The refrigerating machine oil composition is preferably applied to refrigerators having a sliding portion which is made of an engineering plastic material, or provided thereon with an organic coating film or an inorganic coating film. The refrigerating machine oil composition has a low viscosity, an improved energy saving performance, a good sealability and an excellent compatibility with a refrigerant and, therefore, can be suitably used in various refrigerating application fields, in particular, in closed-system refrigerators.