The phase transition in amorphous selenium under high pressure was studied. The high pressures were generated using a diamond‐indentor technique. From the behavior of electrical resistance of amorphous selenium under high pressure, it was found that amorphous selenium at room temperature starts transforming to a crystalline phase when the pressure is near 97 kbar. The effect of temperature on the electronic transition in amorphous selenium under high pressure was also studied. Amorphous selenium was heated to approximately 80 °C; when under a pressure of 26 kbar, it transformed to a conducting phase. The conducting phase was retained for hours at 26 kbar after the temperature was lowered to room temperature.