The purpose of this study was to investigate the level of the role stress and needs of special education teachers who also involve in diagnosing students with disability using psychometric assessment tools at elementary and secondary schools. A survey research was conducted in this study. Subjects were special education teachers who also involve in diagnosing student disabilities using psychometric assessment tools at elementary and secondary schools in Taiwan. A total of 336 surveys were mailed out, and 316 completed surveys were returned. A self-developed questionnaire, “Investigation of Stress and Needs of Special Education Teachers Involving in Psychological-Assessment” was used to collect data. The data was statistically analyzed using descriptive statistics, t-test, and one-way analyses of variance (ANOVAs). The major conclusions were as follows: 1.Special education teachers participating in psychological-assessment demonstrated a medium level of role stress. 2.Special education teachers participating in psychological-assessment demonstrated a high level of needs. 3.The role stress of special education teachers who also involving in psychological-assessment was influenced by age, years of teaching in special education, years of experience participating in psychological-assessment, school area, and the level of psychological-assessment. 4.The needs of special education teachers who also involving in psychological- assessment were influenced by the years of teaching in special education, grade level taught, the number of students assessed, and the level of psychological-assessment. 5.There were high level needs of special education teachers who also involving in psychological-assessment in “Simplify the identification of the business and the number of steps” and “appropriate allocation of work Finally, according to the above results, several suggestions were offered for the education administrators and researchers.