This study aims to evaluate the levels of professional competency among high school teachers as well as to identify the differnces based on gender and work experience, as the teachers' professional competency level is of paramount importance in quality of teaching and learning and students' achievements. The study sample involved 327 teachers from various fields randomly selected from 12 schools in Pekanbaru, Indonaisia. The study used test with 33 questions to measure the teachers' professional competency. Overall results show that the level of professional competencies is generally at an average level. The result shows that there is significant difference between female and male teachers in terms of mastery of professional competency. In addition, the data shows that there is significant difference between more experienced and less experienced teachers regarding mastery of professional competency. The implication is that the program, run by schools or ministery of education, to implement to upgrade the professional competency of teachers should consider the teachers' backgrounds to make sure its effectiveness.