A new approach has been developed for the monitoring of linear alkylbenzene sulfonates (LAS) (C 10 –C 13 ) in sewage sludge. It is based on microwave-assisted extraction (MAE) prior to high performance liquid chromatography coupled with diode array (HPLC-DAD) and fluorescence (HPLC-FL) detectors. Column Zorbax XDB-C8, 150mm×4.6mm i.d., 5μm particle size was used as well as acetonitrile–water containing 0.1M NaClO 4 (65:35) and isocratic elution. Compounds were isocratically eluted over 6min runtime at a flow rate of 1mLmin −1 . Since polar interferences are eluted between 0 and 2min, they do not interfere in the analysis. The column was thermostated at a temperature of 25°C. For the determination of LAS, DAD-UV (λ ex =225nm) and fluorescence (λ ex =225nm, λ em =295nm) detectors were employed.The main factors affecting the extraction efficiency (extractant volume, microwave power and irradiation time) were optimized using a compost sludge. The detection limit for total LAS in the sludge was <5mgkg −1 . The extraction of C 10 –C 13 homologues is carried out by using an extraction time of 10min and 5mL of methanol; whereas Soxhlet needs a 12h extraction. The method did not require clean-up or preconcentration steps. Concentration levels of LAS were between 13037mgkg −1 for digested sludge and 2492mgkg −1 for compost sludge.