The theoretical interpretation of the current neutrino phenomenology is reviewed, in the context of three and four neutrino mixing. We discuss the status of atmosphericv&mgr;oscillations and the recent indications from the KEK‐to‐Kamioka (K2K) experiment. We also review the status of solarveoscillations after the Sudbury Neutrino Observatory (SNO) measurements. The three‐neutrino mixing scenario emerges as a consistent theoretical interpretation of solar, atmospheric, and reactor data. Conversely, the inclusion of LSND accelerator data in an extended four‐neutrino scenario generates a “tension” between data subsets in global fits. We also comment about the role of possible new neutrino interactions. © 2003 American Institute of Physics