Meir has published more than 120 papers in refereed journals. Early in his career, he concentrated on transport through quantum dots, explaining the Coulomb oscillations in the measured electric current. In the process he derived the Meir-Wingreen formula for the electric current through interaction system, a now textbook formula. Later on he made numerous contributions to the field of transport in disordered systems, in particular to the issue of phase transitions in such media, such as the metal-insulator transition in two-dimensions and the Superconductor Insulator Transition in thin films, and to the field of strong correlation effects in mesoscopic devices, in the particular the manifestation of the Kondo effect. In the latter context he suggested a solution for the long standing puzzle of the 0.7 anomaly – the observation of a step in the conductance of quantum point contacts, around the value of 0.7 2e /h (where e is the electron charge and h the Planck constant), in addition to the expected integer steps. This explanation is based on an emergence of a quasi-localized state in the quantum point contact, associated with slow electrons above the point contact barrier, an observation that has been verified experimentally. In recent years he has extended his research to the field of biology, together with his colleague Ned Wingreen from Princeton University.