The ability to perceive similarities between musical notes one octave apart has been documented in all ages including infants. Whether the octave relationship as an aspect of similarity in speech stimuli is as robust in speech tokens is unknown. The purpose of this study was to examine whether children demonstrate an awareness of this octave relationship in the production of speech stimuli during speech imitation tasks. Eleven children, age 4;7 to 6;9, imitated nonwords and sentences presented by male adult voices, at pitch levels below young children’s vocal ranges. Results show that the participants imitated the stimulus pitches one octave higher. The evidence was particularly robust in the nonword imitation task, where the low pitch levels in the stimulus required the children to adjust their conversational pitch levels downward to produce pitches at an octave above the stimulus. We conclude that young children are capable of perceiving the octave relationship as a salient aspect of similarity in speech, and that they utilize this aspect of similarity when imitating low-pitched speech stimuli below their vocal ranges to achieve a more authentic sounding reproduction of the stimulus.