The herbicide, glufosinate ammonium is widely used as crop protection for food crops and also in oil palm plantations. The herbicide is used to control weeds and also as a dessicant agent for land clearing. In this work, glufosinate ammonium was extracted from crude palm oil (CPO) samples using a modified QuEChERS (quick, easy, cheap, effective, rugged and safe) method. This method was based on a simultaneous extraction and clean-up steps which required minimum sample handling. The extraction was performed using 5.0 ml deionised water, (0.1% formic acid) and dichloromethane. The glufosinate ammonium residue was extracted from CPO samples using a mini shaker and centrifuged for 10 min at 2500 rcf. The extracts, following pre-concentration were clean enough for direct injection into the LC-MS/ MS. Quantitative recoveries from 84%-109% were obtained for samples spiked with three concentration levels of 0.005, 0.05 and 0.5 μg ml^-1. The correlation variation (CV) percentage for reproducibility and repeatability of replicate extractions were less than 13% and 10% respectively. The limit of detection and limit of quantification was 0.002 μg litre^-1 and 0.025 μg kg^-1 respectively. The results obtained demonstrated that the method has achieved the requirements of the criteria for acceptance of single laboratory method validation. Determination of glufosinate ammonium residues in Malaysian CPO samples were carried out and the residues were not detected in the analysed samples.