This study examined the relationship between teachers’ assessment practices and learners’ problem-solving skills on their academic performance in the public secondary schools of San Miguel, Bulacan, during the School Year 2025-2026.The sampling technique employed for teacher and school leader respondents was total population sampling, while stratified sampling was used for learners. An explanatory sequential mixed methods design was applied, utilizing survey questionnaires and written explanatory essays. The participants included 59 mathematics teachers, 5 school leaders, and 383 Grade 7 to 10 learners from public secondary schools. Statistical tests such as t-tests, Analysis of Variance (ANOVA), and Pearson’s correlation coefficient analyses were conducted to interpret the data. The findings of the study revealed a significant difference in teachers’ assessment practices when grouped according to the demographic variable of age. However, no significant difference was observed between sex, plantilla position, highest educational attainment, years in service, and number of trainings/seminars and teachers’ assessment practices. Additionally, the study found no significant difference in the evaluations of assessment practices between the teachers and their school leaders. Furthermore, the study identified a significant relationship between teachers’ assessment practices, along with learners’ problem-solving skills, and learners’ academic performance. Based on these findings, different programs of activities were developed to address the identified needs and enhance classroom assessment practices and learners’ problem-solving skills.