While interpersonal communication has been widely examined in the language-learning area, the role of attachment anxiety in shaping foreign language anxiety (FLA) and learners’ second-language willingness to communicate (L2WTC) remains insufficiently understood. This study investigated the relationship among attachment anxiety, FLA, and L2WTC in 193 college students using structural equation modelling. The structural equation modelling results indicated that: (1) higher attachment anxiety predicted greater perceived FLA and lower L2WTC; and (2) FLA significantly mediated the relationship between attachment anxiety and L2WTC. These findings highlight attachment anxiety as an important individual-difference factor in L2 communication and learning. They also suggest that interventions to enhance L2 participation may be more effective when they explicitly target learners’ underlying emotional and psychological vulnerabilities.