Time‐of‐flight measurements have been performed on HgI2. The electron drift mobility varies between 55 and 75 cm2/V s for fieldsE≤20 kV/cm. The plot of the electron drift velocity versusEexhibits a maximum forE∼80 kV/cm; beyond this value the differential mobility becomes negative (∼−5 cm2/V s). an electron trapping time&tgr;e+is found larger than 100 ns. Our measurements also yield estimations of the hole mobility and of the hole trapping time.