We describe the vocal repertoire of the Yellow-faced Parrot (Alipiopsitta xanthops) from recorded vocalizations and also flock sizes in Brasília (Brazil) during 2006. Vocal communication signals are both long-range and short-range sounds. We describe seven call types: flight call (long-range), long-range alarm call, congregation call (long-range), two agonistic calls (long-range/short-range), sentinel call (short-range), and a short-range alarm call. The flight call is equivalent to the functional song and contains the species-specific recognition code. Flight calls may also be uttered when perched and, when in quick series, function as long-range alarm calls. Long-range alarm calls become a high intensity congregation signal when several individuals overlap and, despite degradation and attenuation, may contain the species-specific code over distances of 800 m. The average (±SD) feeding flock size was 7.7 ± 8.2 individuals (n = 116) while the roosting flock size was 79.1 ± 10.5 individuals (n = 7). Short-range calls maintain communication while minimizing detection. High intensity vocalizations allow long-range communication, improving feeding efficiency through use of large areas and stimulating late afternoon roost congregations. Low intensity vocalizations maintain communications without providing the position of the parrot.