A simple and time-saving method of analyzing images obtained from transmission electron microscopic (TEM) investigation of nanostructured transition metal and metal oxide colloids has been developed. It is based on computer image processing using the routine MORFO of the commercially available IMAGIC-5 software package. This high-throughput method provides statistically meaningful data such as the mean value of the colloidal particle diameter, number of nanoparticles considered and standard deviation.