The possibility of exposure to high static magnetic fields altering cognitive performance in human volunteers was tested in a strictly controlled fashion. 24 participants conducted 6 different well-established paradigms covering a variety of cognitive processes. Sessions took place inside a 3T magnet with the main magnetic field being switched on and off. The analysis of reaction time and accuracy revealed no significant effect of the magnetic field in any of the 6 tasks related to the static field. The results indicate that exposure to a 3T field does not alter performance in cognitive tasks.