The constituency was used for one electoral revision only, being abolished under the Electoral (Amendment) Act 1974. The areas in County Donegal were mostly incorporated into the new Donegal constituency, while the more northerly Leitrim territories and the southern area of Donegal (around Bundoran and Ballyshannon), were incorporated into the substantially revised Sligo–Leitrim constituency.
Ballintra, Ballyshannon Rural, Ballyshannon Urban, Bundoran Rural, Carrickboy, Cavangarden, Cliff, in the former Rural District of Ballyshannon;
Ballintra, Binbane, Bonnyglen, Clogher, Corkemore, Donegal, Dunkineely, Eanymore, Grousehall, Haugh, Inver, Laghy, Lough Eask, Pettigoe. Tantallon Tawnawully, Templecarn, Tullynaught, in the former Rural District of Donegal;
Magheraclogher (with the exception of the townland of Glentornan), Meenaclalp in the former Rural District of Dunfanaghy.
Annagary, Aran, Ardara, Crovehy, Crowkeeragh, Crownarad, Dawros, Doocharry, Dunglo, Fintown, Glencolmcille, Glengesh, Glenleheen, Glenties, Graffy, Inishkeel Kilcar, Kilgoly, Killybegs, Largymore, Letter macaward, Maas, Maghery, Malin Beg, Mulmosog, Rutland, Tieveskeelta, in the former Rural District of Glenties;
Altnapaste, Castlefinn, Cloghan, Cloghard Convoy (with the exception of the townlands of Aughagault, Aughagault Big, Breen, Drumkeen, Mullaghfin, Stralongford, Treantaboy), Dooish, Gleneely, Goland, Killygordon, Knock, Stranorlar, Urney West, and the townlands of:
Aghawee, Ardnaglass, Ballybogan, Camus, Churchtown, Gortin South, Gortnavilly, Legnabraid, Tirkeeran, Untshinagh Lower, Unshinagh Upper, in the district electoral division of Clondeigh South; Ardvarnock Glebe, Deerpark, Flemingstown, Kiltole Tullydonnell Lower, Tullydonnell Upper, in the district electoral division of Figart; in the former Rural District of Stranorlar;
Aghalateeve, Aghanlish, Aghavoghill, Gubacreeny, Kinlough, Melvin, Tullaghan, in the former Rural District of Kinlough;
Ballaghameehan, Belhavel, Cloonclare, Cloonlogher, Drumahaire, Glenade, Glenaniff, Glenboy, Glencar, Glenfarn, Killarga, Kiltyclogher, Lurganboy, Manorhamilton, Munakill, Sramor in the former Rural District of Manorhamilton."
Note: The columns in this table are used only for presentational purposes, and no significance should be attached to the order of columns. For details of the order in which seats were won at each election, see the detailed results of that election.
^Breslin was Ceann Comhairle from 1967 to 1973. As outgoing Ceann Comhairle, he was automatically re-elected at the 1969 and 1973 general elections.
^As outgoing Ceann Comhairle, Breslin was returned automatically under Article 16.6 of the Constitution and the Electoral Act 1963.[8]
1970 by-election
Following the death of Fine Gael TD Patrick O'Donnell, a by-election was held on 2 December 1970. The seat was won by the Fianna Fáil candidate Patrick Delap.
^As outgoing Ceann Comhairle, Breslin was returned automatically under Art. 16.6 of the Constitution and the Electoral Act 1963, as adapted by the Electoral (Amendment) Act 1969.[10] He was elected again as Ceann Comhairle on 2 April 1969, leaving the Fianna Fáil parliamentary party.[11]