Research data supporting "Droplet microfluidics for the highly controlled synthesis of branched gold nanoparticles". The article was accepted for publication in January 2018 in the journal "Scientific Reports". Electronic supporting Information is available from the publisher (Nature Publishing Group - NPG). The data is provided with a description in pdf and a structured set of two folders compressed in zip, each correlating to a specific data type presented in the published article. Folder 1: Images - containing images as acquired before any software treatments such as cropping or light/contrast adjusting. Folder 2: Data sheet for histograms – containing csv files with measurements of droplet size for creating histograms shown in Supplementary Information included in the published manuscript.