This study aimed to investigate whether and how willingness to communicate, communication in English anxiety, behavioural inhibition and action predict perceived second language (L2) fluency. The study also looked at whether L2 proficiency moderates the strength of relationships between these affective factors and L2 perceived fluency. One hundred learners of English were recorded while doing the Suitcase task (a monologic task) and were asked to complete a series of questionnaires and proficiency tests. Speech samples were then prepared for presentation to 26 experienced language teachers (and highly proficient users of English) as raters. Their task was to rate the speech samples in terms of perceived fluency. Results revealed that while willingness to communicate is a strong and positive predictor of perceived fluency, communication in English anxiety negatively predicts perceived L2 fluency. We also found that L2 proficiency does not seem to moderate the relationship between perceived fluency and willingness to communicate (WTC), but it does change the partial correlation figure for communication in English anxiety from r = -0.24 (p = 0.013) to r = -0.38 (p < 0.001). This variation suggests that less proficient L2 speakers' perceived fluency could be more severely affected by communication in English anxiety.