Urban arboviral diseases represent a persistent epidemiological challenge for the Brazilian Unified Health System (SUS), requiring institutional resilience and health compliance from local governments. Objective: To analyze the resilience of municipal health systems in responding to urban arboviruses in a health region of Espírito Santo, Brazil, using secondary data from the Integrated Instrument for the Assessment of the Response to Arboviruses (IIARA 2026), while preserving the anonymity of the federated entities. Methods: Observational, descriptive and analytical ecological study based on aggregated secondary data from 23 municipalities. Forty-eight criteria distributed across six thematic axes were assessed. The Resilience Index (IR%) was calculated per axis and globally, applying the "Deal Breaker" (Critical Cut-off) rule to the risk classification criteria in primary and hospital care. Results: The mean regional global IR was 67.15% (range 40.3%–89.6%). The Epidemiological Surveillance axis showed the best performance (87.7%), whereas Management and Governance showed the greatest fragility (41.4%). Only six municipalities achieved the Silver Seal; four municipalities with global scores above 70% were withheld by the Deal Breaker due to failures in care risk classification, preventing certification. Conclusion: The IIARA proved to be an effective health compliance tool, revealing significant regional heterogeneity. The Deal Breaker rule fulfilled its role by preventing the certification of municipalities with critical care fragilities, pointing to the need for priority interventions in local governance and in risk-classified reception.