An oil-based inkjet ink can be provided which prevents dye conversion of a dye lake pigment contained in the ink, prevents adhesion of the ink to the nozzle plate, and yields excellent drying properties for printed items. The oil-based inkjet ink contains a dye lake pigment, a pigment dispersant and a non-aqueous solvent, wherein the non-aqueous solvent contains a silicone oil having a surface tension of at least 20 mN/m but not more than 28 mN/m. The surface tension of the silicone oil is preferably at least 22 mN/m but not more than 26 mN/m.