The study investigated intentions and motivating factors of using impoliteness in interlanguage complaints by English as a Foreign Language (EFL) learners. Empirical data were elicited by means of oral discourse completion tasks and questionnaires from 42 Indonesian learners of English. Post-structured interviews were conducted to obtain the intentions and reasons of deploying impoliteness in the complaints. The results reveal that impoliteness is triggered by three general motivating factors; speaker-related factors, target person-related factors, and contextual factors. A number of intentions of deploying impoliteness are found, and they suggest that impoliteness is a mean to an end rather than an end itself.