| Name | Population | Area
| Density
| Component localities | Established |
| Alba Iulia | 144,341 | 910 | 159 | Cities of Alba Iulia and Sebeș, town of Teiuș and 8 communes | 2007 |
| Bacău | 319,624 | 1,065 | 300 | City of Bacău, town of Buhuși and 22 communes | 2007 |
| Baia Mare | 244,238 | 1,388 | 176 | City of Baia Mare, towns of Baia Sprie, Cavnic, Seini, Șomcuta Mare and Tăuții-Măgherăuș and 13 communes | 2006 |
| Botoșani | 162,318 | 528 | 307 | City of Botoșani, town of Bucecea and 7 communes | 2012 |
| Brașov | 476,893 | 1,745 | 273 | Cities of Brașov, Codlea and Săcele, towns of Ghimbav, Predeal, Râșnov and Zărnești and 11 communes | 2006 |
| Bucharest | 2,536,859 | 1,821 | 1,393 | City of Bucharest and all of Ilfov County including towns of Voluntari, Pantelimon, Buftea, Popești-Leordeni, Bragadiru, Chitila, Otopeni, Măgurele | 2016 |
| Cluj | 433,247 | 1,603 | 270 | City of Cluj-Napoca and 19 communes | 2008 |
| Constanța | 491,746 | 2,121 | 232 | City of Constanța, towns of Eforie, Murfatlar, Năvodari, Ovidiu and Techirghiol and 10 communes | 2007 |
| Corvina (Deva–Hunedoara) | 173,393 | 410 | 423 | Cities of Deva and Hunedoara, towns of Călan and Simeria and 3 communes | 2008 |
| Craiova | 392,898 | 1,499 | 262 | City of Craiova, towns of Filiași and Segarcea and 21 communes | 2009 |
| Drobeta-Turnu Severin | 141,837 | 555 | 256 | Cities of Drobeta-Turnu Severin and Orșova and 5 communes | 2019 |
| Iași | 492,556 | 808 | 610 | City of Iași and 13 communes | 2004 |
| Oradea | 277,605 | 754 | 368 | City of Oradea and 11 communes | 2005 |
| Piatra Neamț | 166,974 | 461 | 362 | City of Piatra Neamț, town of Roznov and 8 communes | 2013 |
| Pitești | 228,554 | 479 | 477 | City of Pitești, town of Ștefănești and 7 communes | 2009 |
| Ploiești | 363,089 | 717 | 506 | City of Ploiești, towns of Băicoi, Boldești-Scăeni and Plopeni and 10 communes | 2009 |
| Râmnicu Vâlcea | 191,934 | | | City of Râmnicu Vâlcea, towns of Băbeni, Băile Govora, Băile Olănești, Călimănești and Ocnele Mari and 14 communes | 2013-2015
|
| Reșița | 117,612 | 777 | 151 | City of Reșița, town of Bocșa and 8 communes | 2013 |
| Roman | 162,533 | 1,121 | 145 | City of Roman and 24 communes | 2009 |
| Satu Mare | 250,290 | 2,251 | 111 | Cities of Carei and Satu Mare, towns of Ardud and Tășnad and 22 communes | 2013 |
| Suceava | 211,708 | 682 | 310 | City of Suceava, town of Salcea and 13 communes | 2011 |
| Târgu Mureș | 230,143 | 695 | 331 | City of Târgu Mureș, town of Ungheni and 13 communes | 2006 |
| Timișoara | 468,430 | 1,080 | 388 | City of Timișoara and 14 communes | 2008 |
| Vaslui | 149,601 | 541 | 277 | City of Vaslui and 10 communes | 2015 |
| Zalău | 153,206 | 1,048 | 146 | City of Zalău, towns of Cehu Silvaniei, Jibou and Șimleu Silvaniei and 14 communes | 2015 |