The present study investigated the timing of backchannel onsets within speaker’s own and dialogue partner’s breathing cycle in two spontaneous conversations in Estonian. Results indicate that backchannels are mainly produced near the beginning, but also in the second half of the speaker’s exhalation phase. A similar tendency was observed in short non-backchannel utterances, indicating that timing of backchannels might be determined by their duration rather than their pragmatic function. By contrast, longer non-backchannel utterances were initiated almost exclusively right at the beginning of the exhalation. As expected, backchannels in the conversation partner’s breathing cycle occurred predominantly towards the end of the exhalation or at the beginning of the inhalation.