The present work provides a methodology for automated image processing and classification of four types of insulators used in Overhead Power Distribution Lines (OPDLs). To this end, a didactic distribution network was developed to capture photos of the insulators at an external environment as well as a studio to acquire images at a controlled environment. Subsequently, the image attributes where extracted and used as inputs for diferent trained classifiers such as neural networks, suport vector machine, decision tree, n-nearest neigbors, naive-bayes and hidden markov model, for a gradual mixing ofthe databases (studio and external imagens). The classification efficiencies where compared considering the application of principal components analysis (PCA) to identify the minimum information required for the classification.