Studies on listeners’ perceptions of speech fluency have typically focused on numeric L2 fluency assessments and rarely addressed individual differences in L1 speech fluency qualitatively. The objective of the present study was to examine how listeners attend to speakers’ L1 speech when assessing the speakers’ L2 and L3 fluency. In the study, 37 listeners were presented with freely produced L1 Finnish, L2 English (Experiment I), and L3 Swedish (Experiment II) speech by Finnish-speaking and Finnish–Swedish bilingual speakers (N=30). The listeners first listened to the speakers’ L1 Finnish speech before assessing their target language fluency and then commented on how hearing the L1 speech samples affected their ratings. A qualitative analysis focusing on the listeners’ comments revealed that listeners attend to both temporal and non-fluency related features in L1 speech when assessing target language fluency, but there were clear individual differences across listeners’ intuitive approaches to L1 speech.