The present study deals with the frequency response of multi-cracked structural systems with uncertain damage and subjected to stochastic excitations. In the context of a mixed probabilistic and non-probabilistic approach, aim of the proposed procedure is to provide the range of variability of the stationary stochastic response (in terms of Power Spectral Density function) of multi-cracked linear elastic structures with uncertain-but-bounded damage subjected to Gaussian random excitation via interval analysis. The proposed procedure relies on the definition of a model for the cracked members with fully open cracks to represent the damage; the modeling of the cracks depths as interval (or uncertain-but-bounded) variables; the evaluation, within the context of the frequency domain, of the parametric interval frequency response function (FRF) matrix by applying the so-called Interval Rational Series Expansion (IRSE) and finally the determination of the upper and lower bounds of the nodal stationary stochastic interval response. The objective is achieved by exploiting an explicit approximate expression of the interval FRF matrix properly derived for damaged structures in presence of uncertain parameters.