Curricula in different countries emphasize that teachers implement problem-based learning (PBL) practices to develop students with problem-solving skills and enhance their academic performance. However, several studies have revealed that academic performance among students, particularly in mathematics, is low, particularly in Tanzania. Using a cross-sectional research design, this study examined students' perceptions of mathematics teachers' implementation of PBL practices in secondary schools. Data from 357 students in the Arusha City Council were collected via questionnaires. Descriptive statistics, an independent samples t test, and two-way multivariate analysis of variance were used to analyze the collected data. In total, 75.25% of the students reported high perceptions of the implementation of PBL practices. School type was significantly different, F(6, 350) = 5.552, p < 0.001, whereas gender was not. The study recommends training teachers in PBL practices, specifically small group discussions, student-centered learning, and the teacher, as facilitators to enhance academic performance in mathematics.