This paper focuses on the formulation and validation of a novel perturbation method for the prediction of the forced response of mistuned bladed disks. At the contrary of most previous methods, this approach leads to a convergent series representation over the entire range of blade–disk coupling levels for small mistuning. The dominant parameter affecting the magnitude of the largest mistuning for which convergence occurs is shown to be the system damping with a weaker effect of the blade–disk coupling. Examples of application on a single degree-of-freedom per blade model and the reduced order model of a blisk demonstrate the potential of this novel approach. Finally, the applicability of this technique for the optimization of intentional mistuning pattern is shown.