This qualitative-quantitative exploratory design sought to determine the factors associated with the attributes and practices of high-performing secondary mathematics teachers.The study underwent three phases: Phase 1-Exploratory; Phase 2-Generating and judging measurement Items; and Phase 3-Development and Reliability Index of MTES . Eight outstanding mathematics teacher awardees and 156 high-performing mathematics teacher in Iloilo were involved in the study. Five of the outstanding mathematics teacher awardees were interviewed and two underwent class observations. Their respective colleagues, administrators and students were included to triangulate the results.The study made use of survey 1, survey 2, interview guide and observation checklist in phase 1. A rating questionnaire that was developed from phase 1 was used in phase 2. Frequency count, mean, and standard deviation were utilized to determine the mathematics teacher's common professional qualifications and top 20 practices. Friedman ANOVA by ranks was used to identify whether there is a significant difference in the practices of high-performing high school mathematics teachers when paired according to groups.In Phase 3, factor analysis was employed to aid the development of Mathematics Teachers Evaluation Scale (MTES). The Cronbach's alpha was determined to know the internal consistency of MTES. The study revealed that there were significant difference in teachers' professional characteristics and teaching qualities when group according to years of experience, and type of school. High-performing mathematics teacher have at most five years of teaching experience, attended math seminar for 11-15 times, are PBET/LET passer with rating from 76-80, use English and mother tongue in teaching, with "very good" pedagogical content knowledge, and with units towards master's degrees. Factors associated with the attribute of high-performing mathematics teachers include teacher's expectations and outlook in mathematics teaching, strength and responsibilities, affective domain, social relationship, classroom management, poise and emphasis in teaching. The Mathematics Teacher Evaluation Scale (MTES) has a very internal consistency with Cronbach's alpha 0.99. Truly, there is a need to emphasize mathematics teacher quality and teaching standards in the Philippines. The researcher recommends that this study will be expanded to widen our perspective and meet realistic standard that truthfully exist in our society.