Use of different teaching materials and curriculum for the same subjects is always a confounding factor in studies investigating teacher characteristics and student achievement. The purpose of this study is to understand the effects of different teacher qualities on student achievement in high schools with a standards-based curriculum delivered over a blended learning environment. Utilizing quantitative research approach, this study investigates the effects of teacher characteristics and teaching practices in a course offered through Cisco Networking Academy, which has a standards-oriented curriculum delivered online. Participants in the study were 226 teachers and 3299 students from Networking Academies located in the USA. The findings suggest that certain teacher characteristics such as teaching experience, degree, and primary teaching field do not have effects on student achievement.