The South Ghadames basin, Libya, near-surface geology consists of a Tertiary-Cretaceous carbonate layer overlying Jurassic clastics. This leads to a strong velocity inversion in the near surface that, combined with the absence of a stable refractor, generates serious statics issues in an area where low relief structures are expected. We propose to use surface-wave analysis and inversion as a tool to build a geologically consistent near-surface velocity model. The geology makes the surface-wave inversion particularly challenging because of the superposition of different modes (Rayleigh, Lamb, and S-guided). To combat these challenges, a new inversion approach, which is able to deal with different modes, was applied.