Alexei Smirnov graduated from MSU Faculty of Physics of Moscow State University in 1974. In 1977, he began to work at the Institute for Nuclear Research (INR) of the Academy of Sciences of the USSR, where he received his Candidate of Sciences degree in 1979. In 1989, he received a degree of Doctor of Physical and Mathematical sciences. He also taught at the Faculty of Physics of Moscow State University in the period from 1982 to 1990.
Smirnov joined the International Centre for Theoretical Physics (ICTP) in Trieste, Italy in 1992 as a staff-associate while continuing his affiliation with INR (Moscow) as a leading research scientist. He became a staff member with ICTP in 1997 and presently holds the position of principal research scientist.
In the following years Smirnov and his colleagues developed a number of aspects of theory and phenomenology of neutrino conversion in various media. Currently Smirnov is working on implications of the obtained neutrino results for fundamental physics (quark-lepton complementarity, unification, etc.) as well as on future programs of studies in neutrino physics.