The weathering performance of polymeric backsheets is most accurately assessed by outdoor exposure to natural weathering and examination of their performance characteristics by observing changes in properties. The main drawback of natural weathering is the long exposure time. Therefore, also existing qualification tests for photovoltaic (PV) components suggest accelerated artificial aging tests. This should lead to similar materials degradation as long-term outdoor exposures cause. However, it is necessary to establish connections between field performance of polymer products and accelerated materials durability testing in order to better predict the service life of a polymer product. Therefore, the main focus of this work was to evaluate the effect of natural and artificial aging on multilayer backsheet films for PV modules. For this reason, different backsheet films were naturally and artificially aged. Subsequently the optical, chemical, mechanical and thermal properties were characterized. In general, only some changes in properties after up to 3000 h of accelerated aging can be correlated with natural weathering for 2.5 years. The degradation mechanism of the polymeric part during natural weathering has to be considered when trying to simulate natural aging conditions in order to choose the right parameters for artificial aging. Thus, the right test design for artificial aging tests is highly important, as well as the consideration of the degradation mechanisms when trying to simulate natural aging conditions. • Xenon aging didn't provoke same changes in optical properties as natural weathering. • UV-fluorescence aging with standardized parameters was the most harmful test. • The used artificial aging tests (ISO4892) only partially simulate natural aging. • Different microclimatic conditions were found for outdoor and indoor weathering.