Artificial Intelligence (AI) is increasingly being adopted in education to enhance assessment and feedback processes. This study investigated the perceptions of Grade 10 students and mathematics teachers regarding the use of AI for assessment and feedback in Vietnamese high schools. A quantitative survey was conducted with students and teachers from several high schools in central Vietnam. Data were collected through structured questionnaires and analyzed using descriptive statistics. The findings indicate that students frequently use AI tools such as ChatGPT and Photomath to support mathematics learning and receive immediate feedback. Both students and teachers generally expressed positive attitudes toward AI, recognizing its potential to improve learning effectiveness, personalize feedback, and reduce teachers’ workload. However, concerns were raised regarding the accuracy of AI-generated responses, overreliance on technology, academic integrity, and limitations in digital competencies. The study concludes that AI has significant potential to improve assessment and feedback in secondary mathematics education. To maximize its benefits, schools should strengthen digital infrastructure, provide training for teachers and students, and establish clear guidelines for responsible AI use.