Marine microplastic contamination is globally recognized as a major environmental concern due to its risks to aquatic biota. Developing effective methods to isolate and quantify microplastics from marine matrices is crucial to establish baseline microplastic contamination and monitor trends and distributions in the marine environment. For monitoring it is desirable to have rapid, simple, high-throughput methods that optimize the isolation of microplastics. In this study, we aimed to optimize the elutriation method used to isolate microplastics from beach sediment samples. Here we present a simple elutriation system capable of processing 1 L (~1.7 kg wet weight) of sandy sediment within 3 min. Spiking of clean sandy sediment with common PVC, PET, PE, PS, PE:PP and nylon microplastics of different sizes and shapes provided validation of the system, and when incorporated into a workflow including a subsequent 1 hour density floatation step with potassium iodide, could separate microplastics with a recovery rate of 95.3 ± 3.9% and a clarification rate of 99%. Further investigations should assess the applicability of the elutriation system for more complex sediments from different environments. Future outputs will indicate the relevance of this method for surveys involving large spatial and/or temporal scales, large number and/or volume of sediment samples, and size classes of microplastics that can be bioavailable to the benthic fauna.