This mixed method participatory action research study investigated the relationships of effective teaching strategies and gender based learning environments to pre-adolescent females' self-efficacy of mathematical ability, classroom participatory behaviors, and academic achievement in the area of mathematics. Research-based teaching strategies were used with sixth grade girls who learned mathematics in a non-accelerated single gender environment (n=28) and sixth grade girls who learned mathematics in a non-accelerated mixed gender environment (n=12). Female students in both types of learning environments experienced increases in self-efficacy of mathematical ability, in levels of participatory behaviors, and in academic performance. Although the self-efficacy of mathematical ability of girls in both types of learning environments increased, girls in the mixed gender classroom environment experienced higher growth of self-efficacy than girls in the single gender classroom environment.