Virus-like particles (VLPs) expressed intracellularly by the yeast S. cerevisiae have helped set the framework of a wide range of biologicals, particularly as carriers for viral antigens. This article investigates the use of dynamic light scattering (DLS) for the rapid evaluation of the concentration and purity of VLPs to aid the complex purification strategy. Development of the assay was per formed in a high background process stream (yeast homogenate) and involved a change in the signal proportional to the VLP concentration by addition of antibodies that bind on the VLP surface and detection of that size change by DLS. Overall, the assay was found to provide a significant improvement of rapid monitoring alternatives for VLPs, exhibiting good sensitivity and speed of measurement. Data are given for the use of the DLS-based assay for optimization of VLP release during a yeast cell disruption treatment.