(Click on the column title to sort by that column)
| # | Catholics | Population | Percent Catholic | Diocese | Year | Source |
|---|---|---|---|---|---|---|
| 1 | 168,000 | 1,520,000 | 11.05% | Timisoara | 2004 | ap2005 |
| 2 | 441,449 | 4,024,454 | 10.97% | Alba Iulia (Archdiocese) | 2004 | ap2005 |
| 3 | 106,827 | 1,014,420 | 10.53% | Oradea Mare {Gran Varadino, Nagyvárad} | 2004 | ap2005 |
| 4 | 70,000 | 850,000 | 8.24% | Satu Mare {Szatmár} | 2004 | ap2005 |
| 5 | 258,913 | 4,301,490 | 6.02% | Iasi | 2004 | ap2005 |
| 6 | 96,200 | 10,000,000 | .96% | Bucarest {Bucuresti} (Archdiocese) | 2004 | ap2005 |
|