The aim of this study was to define features of Guillain-Barré syndrome in a large cohort of patients from three Western Balkans countries. Data from adult Guillain-Barré syndrome (GBS) cases from 2009 to 2013 were retrospectively obtained from all tertiary health care centers. During the 5-year period, 327 new cases of GBS were identified with a male to female ratio of 1.7 : 1. The most common GBS variants were demyelinating (65%) and axonal (12%). At nadir 45% of patients were chair-bound, confined to bed, or required assisted ventilation, while 5% died. The crude incidence of GBS in Serbia and Montenegro was 0.93 per 100,000 population, and age-adjusted incidence according to the world standard population was 0.86 per 100,000. Incidence was particularly high in 50- to 80-year-old men. Statistically significant seasonal variations of GBS were not observed. This study of patients with GBS in the Western Balkans allows us to prepare the health system better and to improve the management of patients. This study also opens opportunities for international collaboration and for taking part in the multinational studies on GBS.