ABSTRACT Spontaneous playback refers to involuntary, sometimes insistent “replay” in the mind of the second language being acquired. Anecdotal data led Krashen to hypothesize that this phenomenon is a result of stimulation of the language acquisition device. The present study surveyed 160 foreign and second language students to enlarge the data base. It was found that spontaneous playback is widespread. The data were consistent with Krashen's hypothesis and with the Monitor theory; therefore, it is concluded that the phenomenon is of interest to the profession and merits further investigation.