To evaluate perceptions, attitudes, and clinical experience of Brazilian dental practitioners regarding molar incisor hypomineralisation (MIH). An online survey with 27 questions, covering professional profile data, perceptions, and knowledge on clinical management of MIH, was employed. Descriptive analyses, chi-square, Fisher's exact, and Cramer's V tests were used. Sample comprised 100 participants, equally distributed between those working in private or public sectors. Most private sector practitioners had 21-30years of clinical experience (28%) and master's degree (50%), while most public sector practitioners had 11-20years of clinical experience (32%) and a PhD degree (32%). Most participants (86%) recognized MIH in their practice. Statistically significant differences were observed in frequency (p = 0.001), incidence (p = 0.039), and lesion type (p = 0.043) between practitioners from both sectors. Uncertainly in management was reported by 49%, mainly in public sector. For mild MIH in incisors, no treatment was chosen (43%), and the treatment longevity was the only significant factor reported (p = 0.012). In cases of mild MIH in first permanent molars (FPMs), 51% of respondents opted to keep the affected tissue and apply fissure sealant. Glass ionomer (GI) restoration was commonly indicated for FPMs with severe MIH with moderate loss of structure and sensitivity (38%). In cases with substantial structural loss and pulpal involvement, the most chosen treatment was endodontic intervention combined with preformed crowns. Brazilian dental practitioners face MIH in clinical practice. Although, public sector professionals are less confident in diagnosis and treatment, no significant differences in treatment preferences between public and private sector dental practitioners were identified.