Mavacoxib is a selective cyclooxygenase-2 nonsteroidal anti-inflammatory drug that has been used for management of osteoarthritis and other inflammatory conditions in dogs. The main advantage of mavacoxib over other nonsteroidal anti-inflammatory drugs is its longer plasma half-life, leading to decreased dosing frequency. This study determined the pharmacokinetics of mavacoxib in Caribbean flamingos (Phoenicopterus ruber ruber) after a single-dose oral administration of 6 mg/kg (n = 6). Plasma mavacoxib concentrations were determined using liquid chromatography with mass spectrometry, and pharmacokinetic analysis was performed using noncompartmental methods. Mean peak plasma concentration (C_max) was (mean; range) 2.97 (2.19––4.06) µg/ml; mean time to peak plasma concentration (T_max) was 18.68 (4.00–48.00) hr; mean area under the curve (AUC) was 455 (292–637) hr * µg/ml; and mean terminal half-life (T_1/2) was 74.47 (49.57–161.43) hr. Based on the results of this study, mavacoxib dosed at 6 mg/kg orally in Caribbean flamingos reaches plasma concentrations above the therapeutic concentration established for dogs, but further studies are needed to determine appropriate dosing recommendations in flamingos.