The study aimed to describe the specialized health services and to identify areas of greater difficulty of access to specialized consultations offered by SUS in small cities in the 18th Regional Health Area of Paraná State, Brazil, using case study methodology. The data were collected between January and April 2015. Managers, management teams and the board of directors of the CIS (Consórcio Intermunicipal de Saúde) were interviewed. The 21 studied specialist areas were rated like Sufficient Quota, Insufficient Quota, Inexistent Supply, and Assistance Gap. The services with more difficulty of access were Vascular Surgery, Proctology, Geriatrics, Endocrinology, and Neurology, considered Inexistent Supply/Assistance Gap, and Orthopedics, Neuro-pediatrics, Urology, Rheumatology, Ophthalmology, and Otorhinolaryngology, were considered Insufficient Share. Contribute to the magnitude of the problem: lack of specialist doctors, private sector dependence and de decrease of the Federal and State Governments in financing the Health Sistem. Therefore, the gap in specialized healthcare is complex and difficult to solve in the short-terms, proving that this services have become a "bottleneck" in the SUS.