Purpose - In the dynamical analysis of engineering systems, running a detailed high-resolution finite element model can be expensive even for obtaining the dynamic response at few frequency points. To address this problem, this paper aims to investigate the possibility of representing the output of an expensive computer code as a Gaussian stochastic process. Design/methodology/ approach - The Gaussian process emulator method is discussed and then applied to both simulated and experimentally measured data from the frequency response of a cantilever plate excited by a harmonic force. The dynamic response over a frequency range is approximated using only a small number of response values, obtained both by running a finite element model at carefully selected frequency points and from experimental measurements. The results are then validated applying some adequacy diagnostics. Findings - It is shown that the Gaussian process emulator method can be an effective predictive tool for medium and high-frequency vibration problems, whenever the data are expensive to obtain, either from a computer-intensive code or a resource-consuming experiment. Originality/value - Although Gaussian process emulators have been used in other disciplines, there is no knowledge of it having been implemented for structural dynamic analyses and it has good potential for this area of engineering. copy; Emerald Group Publishing Limited.