A combination magnetic densimeter and viscometer, which essentially simultaneously measures the density and viscosity on 0.3 ml specimens of fluids, is described. A small cylindrical buoy is freely suspended magnetically and coaxially with a larger surrounding cylindrical glass tube which contains the fluid in which the buoy is completely immersed. After calibration, the electrical current in the air core solenoids which magnetically support the buoy measures the density of the fluid while the period of revolution at constant power input determines the viscosity. The density can be measured to the order of magnitude of one part in 106and the viscosity to one part in 104.