The Surface Detector of the Pierre Auger Observatory, an array of 1600 water-
Cherenkov stations in a triangular grid with 1500 m separation between
stations, has the capability to detect neutrinos with energy above 10^17 eV. The
identification through the special characteristics of highly inclined showers is
efficiently performed for neutrinos of all flavours interacting deep in the
atmosphere at large zenith angles as well as for Earth skimming τ neutrinos.
In this talk I review the status of the neutrino search at the Observatory using
about 15 years of data. Restrictive upper bounds on the neutrino flux from
diffuse sources and from point-like steady sources were stablished placing
strong constraints on several models of neutrino production at EeV energies
and on the properties of the sources of ultra-high-energy cosmic rays.
Unrivaled sensitivity in searches for transient sources has been also achieved.