The vocalizations of relatively few bird species have been described in detail, even though vocalizations are an integral aspect of avian life history. We studied the vocalizations of lekking male greater prairie-chickens (Tympanuchus cupido pinnatus) in 2013 and 2014 to provide baseline information for this species of conservation concern. Our objective was to characterize the acoustic components of the four primary vocalizations in terms of their duration (s), sound pressure level (dB SPL), peak frequency (Hz), dominant frequency (Hz), fundamental frequency (Hz), bandwidth (Hz), and nonlinearities (frequency jumps, biphonations, subharmonics, and deterministic chaos). The boom, cackle, whine, and whoop vocalizations were complex and dominated by low-frequency energy. Booms had the longest duration (x̄ = 1.89 s, SD = 0.18), whines and whoops had shorter durations (x̄whine = 0.32, SD = 0.17; x̄whoop = 0.36, SD = 0.07), and cackles had the shortest duration (x̄ = 0.07, SD = 0.02). Booms had the highest sound pressure level (x̄ = 95 dB SPL, SD = 5), followed by whoops (x̄ = 88, SD = 7). Cackles and whines had the lowest sound pressure levels (x̄cackle = 71, SD = 5; x̄whine = 73, SD = 6). Booms had the lowest fundamental frequency (x̄ = 299 Hz, SD = 13), followed by the cackles and whines (x̄cackle = 355, SD = 32; x̄whine = 430, SD = 81). Whoops had the highest fundamental frequency (x̄ = 622, SD = 69). We suggest characteristics that may be useful in future studies of acoustics in the context of behavior or conservation.