Rapid sample preparation methods for the determination of sulfamethazine (SMZ) and its N4-acetyl and desamino metabolites in swine tissues at the 0.1 mg kg-1 level are presented. The methods use sonication-aided extraction with dichloromethane. For SMZ and N4-acetyl SMZ analysis extracts are cleaned up and concentrated on a silica disposable column followed by HPLC on a CP Spher C8 column using acetonitrile-sodium acetate buffer as the mobile phase. For desamino-SMZ analysis the extract was cleaned up and concentrated on a Florisil disposable column, followed by HPLC on a Nucleosil 5-CN column after formation of an ion-pair complex with 1-heptanesulfonic acid. For desamino SMZ peak identification by diode-array UV/VIS detection is also described. Mean recoveries from spiked tissue samples were about 87% (muscle) and 76% (kidney) for SMZ and N4-acetyl SMZ and about 70% for desamino SMZ.