The purposes of this study were to investigate the effects of the use of paper-based and weblog-based electronic portfolios on the writing achievement of limited English proficiency students, to survey the students' attitudes towards the use of the portfolio assessment, and to compare the viewpoints of the students in the control and experimental groups. The study was conducted with 60 second-year hotel and tourism students enrolled in the Writing for the Service Industry course. They had limited English proficiency, as their previous English grades were C or below in average. The simple random sampling technique was used for subject selection and group assignment. Google's free weblog website (located at www.blogger.com) was used as a tool for creating and developing the students' personal electronic portfolios. At the beginning of the course, the students in the control group and the experimental group were trained in the concept of portfolios, and the purposes, content, and criteria used for assessment were discussed with the students. A writing achievement test and a closed-ended questionnaire were used for the quantitative data collection, while the qualitative data were gathered from the open-ended questions, interviews, and reflection. Descriptive statistics and t-tests were employed for the data analysis. It was found that the effects of the use of paper-based portfolios and weblog-based electronic portfolios on the writing achievement were not significantly different, but some promising results of the use of weblog-based electronic portfolios for language learning and assessment are indisputable.