Senior high school education in Ghana has experienced tremendous growth following the introduction of the Free Senior High School (FSHS) policy. Several studies have proven that increased student enrollment presents challenges to effective teaching and learning and academic performance. In view of this, the study explored how teaching and learning are reacting to the recent increase in student enrollment in Ghanaian Senior High Schools (SHSs). In this study, 181 teachers were selected from six SHS within the Ejisu Municipality using the cluster sampling technique in order to examine how changes in student enrollment following the implementation of the FSHS policy have affected teaching and learning. The study adopted trend analysis, with data analyzed using SPSS. The findings showed an impressive, steady increase in student enrollment. It was also found that students’ academic performance generally dipped in the introductory years of the FSHS policy, while some improvements were observed from 2019 forward. However, the study revealed that schools experienced classroom and dining hall congestion, inadequate teaching and learning materials, inadequate hostel infrastructure, and a high student-teacher ratio. The study recommends a multistakeholder collaboration to salvage the infrastructure deficits and their associated challenges that characterize SHSs in Ghana. Keywords: Free Senior High School (FSHS), student enrollment, class size effect, academic performance, Ghana