The purpose of this study is to investigate how international teachers, who were from overseas but taught in the United States, rate effective teacher qualities in three domains; personal, professional, and classroom management skills. The study includes 130 international mathematics, science, and computer teachers who taught in a multi-school charter school system in south-central America. It was found that international teachers perception of effective teachers was similar to findings of other research regardless of nationality as long as teachers enjoys teaching, explain the materials clearly, and grade student work fairly. Univariate ANOVA analysis revealed that international teachers' US teaching experience had statistically significant effect on teachers' ratings of professional skills. Findings were discussed in light of developing more general effective teacher qualities regardless of subject matter.