We present a literature review of experimental studies aiming to characterize soiling and its effects on the generation performance of photovoltaic (PV) systems. The methodology is based on a systematic review of the literature (SRL) through the elaboration and implementation of a conduction protocol, with selection criteria, search strategies, and extraction and summarization procedures. In the search and identification, 3018 primary studies (PSs) are initially obtained, with 151 PSs being admitted for extraction and summarization. The bibliometric analysis identifies the annual distribution of publications, main researchers, means of scientific dissemination, and most used terms as keywords. The short-circuit current (Isc) is usually the parameter most affected by dirt; considering other parameters, different behaviors are identified, depending on the PV technology. The chemical elements most reported are Ca, Si, Al, O, Fe, and Mg; the main mineral compounds are quartz, calcite, hematite, gypsum, and orthoclase.