Résumé : On 27 December 2004, a giant γ flare from the Soft Gamma-Ray Repeater 1806-20 saturated many satellite gamma-ray detectors, being the brightest transient event ever observed in the Galaxy. AMANDA-II was used to search for down-going muons indicative of high-energy gammas and/or neutrinos from this object. The data revealed no significant signal, so upper limits (at 90% C.L.) on the normalization constant were set: 0.05(0.5)TeV-1m-2s-1 for γ=-1.47 (-2) in the gamma flux and 0.4(6.1)TeV-1m-2s-1 for γ=-1.47 (-2) in the high-energy neutrino flux. © 2006 The American Physical Society.