Autophagy is a catabolic process triggered in the cell by a wide range of stress stimuli, both external (including nutrient deprivation) and internal (like the presence of protein aggregates or damaged organelles). First described in yeast, this pathway has recently gained major importance due to its role in several pathologies, from inflammatory processes to cancer or aging. However, its analysis can be easily misinterpreted if it is not done properly, leading to conflicting results. Here, the classical autophagy flux study by Western blot is described, as a first and basic analysis of the status of autophagy in a given system.