This study was designed to investigate factors that influence girls' enrollment and performance in physics in five (28%) 'traditional' national schools in Kenya. Meaningful learning of physics is the hallmark of a technologically competent workforce in science, technology and engineering. However, there is a lower performance index and enrollment of girls opting to study physics at KCSE. The factors of attitudes of students, learners' ability and teacher characteristics were found to affect enrollment and performance of girls in physics. The study showed students' attitude, learner's ability and teacher characteristics, affected girls' enrollment and performance in physics in national schools.However, the girls had better positive attitudes and performance in learner abilities in physics than the boys. The results also showed that teachers of physics in girls' national schools are effective and efficient in instructional designs. The findings of this study may be used to foster positive attitudes towards physics. The methods of physics instruction among girls may also be impacted by constructivism approaches as the results show strong preference to physics practical work.