This study investigated the effectiveness of process-oriented guided-inquiry learning (POGIL) pedagogy in improving male and female undergraduates' academic achievement in science education, in comparison with the conventional lecture method. A non-equivalent, control group quasi-experimental design was used to investigate male and female undergraduates' achievement in science education. Data were collected from 85 second-year science education undergraduates and analyzed using mean, standard deviation, and analysis of covariance. The results show that POGIL pedagogy, as opposed to lecture pedagogy, resulted in improved academic achievement in science education (F (1,82) = 26.66, P = .000, ˂ .05). The data provided evidence to suggest that undergraduates that learned by the POGIL method had a greater grasp of content knowledge than their counterpart that learned by the lecture approach, as evidenced by higher mean achievement scores for POGIL undergraduates. There was no significant influence of gender on the undergraduates' achievement in the POGIL (F (1,37) = .805, P = .375, ˃ .05). The findings of the study have implications for the restructuring of science education teaching environments in the university system by de-emphasizing and discouraging the use of teacher-centered pedagogies and promoting the use of the current student-centered pedagogies for enhancing the undergraduates' academic achievement. The researchers, therefore, recommend that lecturers should organize science educational environments to support active learning strategies for improved undergraduates' academic achievement in science education.