When producing particles of a known size, the monodispersity of the samples in terms of both size and shape is important and often requires a high-resolution technique such as TEM to look at these sample properties. For example, Particle Works, a brand of Blacktrace Holdings Ltd, produce gold nanoparticles which must be highly monodisperse and have high batch-to-batch consistency, with CV values as low as 5% for the size distribution and 2.5% for the batch consistency. Currently, Particle Works use TEM as the primary technique for characterizing their samples for QC. However, TEM is a time consuming and expensive technique that requires an experienced user to perform analysis. In this study we show how the Zetasizer Ultra can be used to identify the majority of 'out of specification' batches of gold nanoparticles and therefore significantly reduce the amount of TEM analysis required.