Photoelectron spectra of size-selected and relatively cold Ni-n(-) (n=1-100) clusters were obtained at three detachment photon energies; 355, 266, and 193 nm. The evolution of the electronic structure of Ni-n(-) clusters from molecular to bulklike behavior was systematically investigated. Well-resolved threshold peaks were observed for small Ni-n(-) clusters (nless than or equal to9), beyond which a single broadband was observed due to the high electronic density of states at large cluster sizes. This spectral change coincides with a dramatic decrease of the magnetic moment in this size range. In addition, narrow and well-resolved spectral features were observed around n=13 and 55, consistent with high symmetry icosahedral structures proposed for these clusters. A sharp threshold peak was observed in the spectra of Ni-19(-) and Ni-23(-), also evident of more symmetric cluster structures. The spectra of Ni-3(-) measured at various photon energies suggested the existence of two isomers. The electron affinities of the Ni-n clusters were observed to follow the prediction of a metallic droplet model at large cluster sizes above n=10 and extrapolate to the bulk work function of Ni at infinite size.