The present paper reports on EFL teachers' and students' attitudes, challenges, and suggestions regarding portfolio assessment in language classes at a higher academic institution in Oman. The sample of the study includes six teachers and 108 students. Data was collected through two questionnaires. Analysis of the results reveals that teachers have low attitude levels, compared to students who have moderate attitude levels, towards using portfolios as an assessment tool for students' learning. Also, both teachers and students met various challenges in using portfolios and suggested different changes to the practice. These findings have several implications for language teachers, as well as language institutions, who should consider including all language skills in assessment portfolios. There should be periodic reviews of portfolio completion by the teacher and students. In addition, the findings of this paper suggest considerations for using e-portfolios.