  Neutrino masses are yet unknown. We discuss the present state of effective
electron anti-neutrino mass from $\beta$ decay experiments; effective Majorana
neutrino mass from neutrinoless double-beta decay experiments; neutrino mass
squared differences from neutrino oscillation: solar, atmospheric, reactor and
accelerator based experiments; sum of neutrino masses from cosmological
observations. Current experimental challenges in the determination of neutrino
masses are briefly discussed. The main focus is devoted to contemporary
experiments.
