This paper explored Korean university EFL students` writing performance and its model, using a qualitative research method. Several categories or themes emerged from in-depth interviews with current research respondents, which were perceived to impact students` EFL writing performance both inside and outside the university classroom. That is, results derived from the analysis of the data encompassed the following categories: (1) EFL learners` cognitive or metacognitive capacity; (2) EFL learners` overall English proficiency; (3) free voluntary reading in English; (4) free voluntary writing in English; and (5) EFL learners` writing apprehension and attitudes towards writing in English. Grounded in the categories above, a conceptual model of Korean university EFL learners` writing performance was eventually offered which could shed light on key components as perceived to have a bearing on writing performance in which korean university EFL learners might engage themselves.