This dataset consists of 16 repeated magnetotelluric (MT) stations collected on Mount Tongariro, New Zealand, before (2009) and after (2013) the 2012 eruption. The data were collected in same locations with similiar instruments. Preeruption and posteruption electromagnetic magnetotelluric measurements determine variation in subsurface electrical properties resulting from changes in magmatic system associated with the 2012 eruptive cycle.