Resistance to aminoglycoside antibiotics is mediated by chemical modifications including phosphorylation, nucleotidylation and acetylation. The largest family of aminoglycoside-modifying enzymes are the amino glycoside 6'-N-acetyltransferase (AAC) enzymes. There are at least 60 of these enzymes but only structural knowledge of five at the time of this structure determination. Here we present the structure of AAC(6')-Ig, an enzyme from the emerging pathogen Acinetobacter haemolyticus, in complex with the aminoglycoside tobramycin. The dimer is most closely related to the CSGID target IDP91869 - AAC(6')-Ih (PDB 4E8O) but reveals the mode of recognition of aminoglycoside substrates.