Abstract: Pesticide adsorption and desorption are important processes that influence the amount of pesticide retained in the soil matrix and its subsequent movement in the soil profile. A study was made on the adsorption-desorption and mobility of the herbicide 2,4-D (2,4-dichlorophenoxyacetic acid) in two ricefield soils in the Kerian district, located in the state of Perak, North West Malaysia. Adsorption studies were conducted using the batch equilibrium technique and mobility was studied using a soil column under laboratory conditions. The adsorption and desorption studies fit the Freundlich equation, the adsorption coefficient (Kd) of the clay loam and clay soils were 33.83 and 18.12 L kg-1 and the 1/nads values were found to be lower than unity. The total percentage desorption from the clay loam and clay soils after the fourth desorption process was 18.31 and 28.33%, respectively. Complete leaching of the chemical through the soil column was not observed under the conditions of the present study, as the chemical was not detected in the leachate. The total amount of 2,4-D found in the clay loam and clay soil columns were 66.96 and 72.28% with 5 mm of simulated rainfall per day. The results obtained indicate the importance of organic matter in adsorption-desorption and mobility of 2,4-D in the Malaysian soils studied.