Effective formative assessment is essential for monitoring learning progress, improving instructional decisions, and providing students with timely feedback; however, evidence regarding teachers’ implementation of formative assessment in junior secondary schools remains limited in Maiduguri Metropolis, Borno State, Nigeria. This study examines how junior secondary school teachers plan formative assessments, implement assessment methods and procedures, and provide feedback on students’ performance. A descriptive survey design was employed, with a population of 1,567 junior secondary school teachers and a sample of 157 respondents selected through simple random sampling. Data were collected using the researchers-developed Junior Secondary School Teachers’ Formative Assessment Practices Questionnaire, which demonstrated acceptable internal consistency (Cronbach’s α = .78) and used a five-point response scale ranging from always to never. Descriptive statistics comprising means and standard deviations were used to answer the research questions. The findings indicate that teachers plan formative assessments by aligning assessment tasks with learning outcomes and taught content and by considering the six cognitive levels of Bloom’s taxonomy. Teachers commonly administer written classroom assessments, design tasks that enable high levels of student achievement, and provide whole-class face-to-face feedback, immediate feedback during task completion, and written comments on assessed work. Nevertheless, teachers rarely sample assessment tasks across all curriculum themes, involve students in group projects, or provide feedback after every formative assessment. The study concludes that although teachers demonstrate several appropriate formative assessment practices, important gaps remain in curriculum coverage, collaborative assessment, and feedback consistency. These findings provide empirical guidance for improving classroom assessment practices and support the recommendation that the Borno State Ministry of Education provide further training and assessment-related professional development for junior secondary school teachers.