Organic-inorganic hybrid perovskite solar cells have exhibited power conversion efficiencies comparable to more established PV technologies thanks to their favourable optoelectronic properties, but low operational stability inhibits their commercialisation and widespread use. Many degradation pathways are possible and most of them are not currently well understood at the nanoscale due to the difficulty of characterising a perovskite solar cell’s complex nanostructure. This work reviews the application of in-situ and operando electron microscopy to visualise the dynamic processes that occur in perovskite solar cells as various stimuli are applied inside a microscope column. Additionally, potential challenges and an outlook on future uses of this technique are briefly discussed.