A nail polish composition, in particular nail polish formulation, is disclosed which is based on a specific solvent-free aqueous polyurethane polymer dispersion, which is derived from at least one isocyanate-terminated ethylenically unsaturated polyurethane pre-polymer in a reactive diluent, after a chain extension reaction with a chain extender bearing isocyanate-reactive groups. The polyurethane pre-polymer comprises at least one (meth)acrylate functional group and at least one isocyanate functional group.