The territorial base of Staecnon-RJ comprises 26 municipalities in the North and Northwest Fluminense region of the State of Rio de Janeiro:
- Aperibé
- Good Jesus of Itabapoana
- Cambuci
- Campos dos Goytacazes
- Carapebus
- Cardoso Moreira
- Casemiro de Abreu
- Conceição de Macabu
- Italva
- Itaocara
- Itaperuna
- Muriaé Slab
- Macaé
- Miracema
- Nativity
- Porciúncula
- Quissamã
- Rio das Ostras
- Saint Mary Magdalene
- Saint Anthony of Padua
- Saint Fidelis
- Saint Francis of Itabapoana
- Saint John of Barra
- Saint Joseph of Ubá
- Trajano de Moraes
- Sweep-Out
