This paper investigates which cognitive abilities predict theinterpretation of complex sentences by older adults.Participants performed a picture-selection task after hearingcomplex and simpler sentences, as well as a broad testbattery of cognitive tests. The results show that differentcognitive factors serve as predictors for the interpretation ofcomplex sentences compared to simpler sentences. Forcomplex sentences, verbal intelligence, cognitive flexibility,and working memory capacity are strong predictors. Ourstudy thus shows that older adults' interpretation of sentencesof varying complexity is influenced by different cognitiveabilities, and stresses the need to take such individualdifferences into account when studying language processing.