Background/purpose: Instructional interaction barriers--including physical, psycho-emotional, perceptual, semantic, and management-related factors--can impede learning and diminish the overall effectiveness of classroom practice. This study examines the barriers faced by mathematics teachers in Saudi Arabia and their differences across gender, school type, school level, and teaching experience. Materials/methods: A descriptive research design was employed using a purposive sample of 270 mathematics teachers from Al-Ahsa schools during the 2023-2024 academic year. Data were collected using a structured questionnaire and analyzed in SPSS 25.0 with independent-samples t(268) tests, one-way ANOVA, and Tukey post hoc comparisons. Results: Male teachers reported significantly higher levels of instructional interaction barriers than female teachers (t(268) = 2.81, p = 0.005, Cohen's d = 0.35). Public school teachers experienced greater challenges than those in private schools (p < 0.05). Secondary school teachers reported higher psycho-emotional, management, and perceptual barriers than primary and intermediate teachers (p < 0.01). Teaching experience was associated with differences in physical and perceptual barriers, with less experienced teachers reporting higher levels of barriers. Conclusion: Demographic and institutional factors meaningfully shape classroom interaction for mathematics teachers. Targeted professional development and structured mentoring--particularly pairing expert teachers with novice ones--are recommended to strengthen teacher-student interaction across educational settings in Al-Ahsa and comparable contexts. Limitations and implications: The study is limited to a single educational region and relies on self-reported data, which may affect generalizability. Future research should employ broader sampling and mixed data sources.