Although portfolios in writing in English as a Foreign Language (EFL) learning are alternative tools, the portfolio process mainly concerns the decisions of language teachers rather than students' perceptions of portfolios. The present study aims to descriptively measure the perceptions of English as a Foreign Language (EFL) students towards portfolio keeping. The sample group in the study consisted of 204 EFL students. A portfolio contribution questionnaire and a portfolio problem questionnaire were used to collect quantitative data. Two results were obtained from the study: (1) portfolio keeping in EFL writing is beneficial to the improvement of vocabulary and grammar knowledge, reading, research, and writing skills; and (2) EFL students perceive some problems during the portfolio keeping process.