The viscosity of mixtures of 2,3,4-trimethylpentane, squalene, 2,2,4-trimethylpentane, 2,2,4,4,6,8,8-heptamethylnonane, polyisobutylene (M = 500 g/mol), ethylbenzene, and 1,2-diphenylethane with ethene at elevated pressures was determined with a rolling ball viscometer. Viscosity measurements were made at 298, 353, and 453 K and pressure up to 200 MPa with an accuracy of [+-]2%. The viscosities of the binary mixtures are described as a function of mass fraction and the viscosities of the pure compounds by an empirical equation. The results are compared with literature data of binary nonassociating systems.