A number of different cosmological scenarios can lead to production of primordial black holes (PBHs) in amounts sufficient to account for all or part of dark matter. In particular, PBH is a generic dark matter candidate in supersymmetric theories. Alternatively, Yukawa interactions of fermions can lead to production of PBH. If dark matter is made up of small black holes, disruption of neutron stars by such black holes could contribute to synthesis of heavy elements and can provide clues to the presence of primordial black holes. I will review theoretical understanding, astrophysical manifestations, and ongoing search for primordial black holes.