This study aimed at developing a valid and reliable scale to determine students' levels of writing self-efficacy. The sample consisted of (208) students from Faculty of Education, Fayoum University. Experts in the field of curriculum and EFL instruction were consulted to establish content validity of the items included in the scale. In addition, a KMO (Kaiser-Meyer-Olkin) sample adequacy test was carried out in the data analysis phase; Bartlett's test was applied to specify the level of factorability for the scale; a principal components factor analysis was carried out for the items in the scale. The total correlation of the items was determined; and correlation measurements between subtitles and total points of the scale were also performed. Also, the Cronbach's Alpha coefficient test was applied to determine the scale reliability. To specify the internal consistency and reliability of the scale, the alpha test focused on ٣٤٤          subtitles, in particular. At the conclusion of these analyses, the results indicated that the writing self-efficacy scale was accepted as a valid and reliable measurement tool.