This study aimed at identifying to what extent Omani teachers use the students' portfolio in basic education grades (5-10) in Muscat. It also aimed at finding out the role of gender and experience variables in influencing the teacher usage of students' portfolios. To achieve its purposes, the researcher constructed a (31 items) questionnaire divided into five dimensions. After ensuring that the study instrument had high reliability and validity values, it was distributed to (176) male and female teachers in Muscat. The study resulted in ordering the dimensions of teachers' usage of students' portfolio descending according to teachers' perceptions as follows: choosing the portfolio content, organizing the portfolio, saving and presenting it, educating students and parents about the portfolio importance and using it in communicating with parents. It was also founded that there were no significant differences in the significance level of (a=, 05) that related to the role of gender in the teachers' usage of students' portfolios. Other conclusion was that there were no significant differences in the significance level of (a=, 05) that related to the role of teachers' experience in the extent to which teachers use the students' portfolios which was concerned with choosing the portfolio content, organizing the portfolio, saving and presenting it except the dimensions of educating students and parents about the portfolio importance and using it in communicating with parents. Based on the above findings, the researchers draw some suggestions and recommendations