Relativistic second-order viscous hydrodynamics at finite temperature is discussed. Using the Weyl-covariant formalism theconstraints by confromal invariance are derived. The transport coefficients, e.g. shear viscosity etc., as a function of temperature are obtained from the strongly coupled N = 4 SUSY theory applying the AdS/CFT correspondence. Recent results from a comparison with RHIC experimental data are quoted.