Purpose <p>This article aims to presented the size-dependent free vibration response of short-fiber-reinforced and perforated nanowires restrained with deformable springs at both ends, taking into account non-local modified couple stress theory.</p> Methods <p>This study is conducted using Euler-Bernoulli beam theory and non-local modified couple stress theory. Hamilton's principle is used to derive the equations of motion of short-fiber reinforced and perforated nanowires. An analytical method based on a Fourier sine series and Stokes' transform is adopted to solve the free vibration problem.</p> Results <p>A number analyses are carried out to examine the effects of the material length scale parameter, short fiber properties, perforation properties and deformable boundaries on the free vibration of the nanowires.</p> Conclusion <p>According to the analysis results, it is determined for SFR nanowires that increases in the Ef/Em ratio and l/d ratio increase the frequencies, while increases in the ρf/ρm ratio decrease the frequencies. Similarly, for perforated nanowires, increment in filling ratio increases the frequencies while increment in number of holes decreases the frequencies. In addition, the non-local parameter and material length scale parameter decreases and increases of both short-fiber-reinforced nanowire's and perforated nanowire's frequecies, respectively.</p>