ABSTRACT In this work, earthquake response spectra are derived for tall, flexible steel pylons with attached heavy masses by using representative far-field records of recent strong motion earthquakes in the Greek domain, as recorded on firm ground. These pylons serve a variety of purposes, such as lighting posts, electric power lines and wind turbines, the latter being a key component in the production of “green” energy. The response spectra are constructed by modelling the combined pylon-mass system as a waveguide, which is the first step for an accurate determination of the displacement functions describing axial and flexural vibrations and for gauging the influence of the attached mass on the solution to the eigenvalue problem. The methodology can be extended to develop response spectra for more categories of structural elements with an attached mass of arbitrary magnitude, for ground motions recorded in other earthquake prone regions, as well as for transient motions at the level of the attached mass.