We report results of investigations of electronic transport properties and lattice dynamics of Al-doped magnesium silicide (Mg2Si) thermoelectrics at ambient and high pressures to and beyond 15 GPa. High-quality samples of Mg2Si doped with 1 at. % of Al were prepared by spark plasma sintering technique. The samples were extensively examined at ambient pressure conditions by X-ray diffraction studies, Raman spectroscopy, electrical resistivity, magnetoresistance, Hall effect, thermoelectric power (Seebeck effect), and thermal conductivity. A Kondo-like feature in the electrical resistivity curves at low temperatures indicates a possible magnetism in the samples. The absolute values of the thermopower and electrical resistivity, and Raman spectra intensity of Mg2Si:Al dramatically diminished upon room-temperature compression. The calculated thermoelectric power factor of Mg2Si:Al raised with pressure to 2-3 GPa peaking in the maximum the values as high as about 8 x 10(-3) W/(K(2)m) and then gradually decreased with further compression. Raman spectroscopy studies indicated the crossovers near similar to 5-7 and similar to 11-12 GPa that are likely related to phase transitions. The data gathered suggest that Mg2Si: Al is metallized under moderate pressures between similar to 5 and 12 GPa. (C) 2014 AIP Publishing LLC.