Certain room‐temperature cholesteric liquid crystals are capable of retaining information on their past history of electric field excitation by exhibiting marked changes in their optical transmission properties. The information retention slowly decays but in many cases persists for at least several days following the removal of excitation. Thus 100 V applied across a 25 &mgr; sample for 10 min caused a change in transmission at 5000 Å from 75 to about 22%. Sixty hours later, the transmission was about 48%.