| Start date | Abbr. | Full name | Closing date | Then called | Remarks |
|---|
| 23 July 1896 | AA | Aubonne-Allaman | 27 August 1898 | AAG | |
| 27 August 1898 | AAG | Allaman-Aubonne-Gimel | 14 May 1950 | | Abandoned |
| 10 November 1885 | AB | Appenzellerbahn | 1 January 1988 | AB' | |
| 1 January 1988 | AB' | Appenzeller Bahnen | | | |
| 6 April 1897 | ABB | Altst�tten-Berneck-Bahn | 8 April 1915 | RhStB | |
| 1 January 1945 | ACT | Azienda comunale del traffico Lugano | 1 January 1970 | ACT' | |
| 1 January 1970 | ACT' | Azienda comunale dei trasporti Lugano | | | |
| 25 August 1906 | AF | Altdorf-Fl�elen | 26 March 1951 | | Abandoned |
| 18 November 1911 | AG | Altst�tten-Gais | 1 January 1947 | SGA' | |
| 28 June 1907 | AGB | Albisg�tli-Bahn | 7 July 1925 | StStZ | |
| 12 September 1896 | AL | Apples-L'Isle | 1 July 1899 | BAM | |
| 5 May 1900 | AL' | Aigle-Leysin | | | |
| 12 November 1918 | AL'' | Alsace-Lorraine | 1 January 1938 | SNCF | |
| 2 April 1907 | AOM | Aigle-Ollon-Monthey | 1 January 1946 | AOMC | |
| 1 January 1947 | AOMC | Aigle-Ollon-Monthey-Champ�ry | | | |
| | APS | Aktion Pro Sächsitram | | | |
| 27 June 1973 | ARB | Arth-Rigi-Bahn | 1 January 1992 | RB' | |
| 19 November 1901 | AS | Aarau-Sch�ftland | 1 January 1957 | WSB | |
| 23 June 1974 | ASB | Aargauische S�dbahn | 1 January 1902 | SBB | |
| 22 December 1913 | ASD | Aigle-S�pey-Diablerets | | | |
| 1 October 1889 | ASt | Appenzeller Strassenbahn | 1 January 1931 | SGA | |
| 12 May 1998 | ATG | AlpTransit Gotthard | | | Standseilbahn Mira-Las Rueras |
| 12 December 1939 | AWW | Appenzell-Weissbad-Wasserauen | 1 January 1947 | AB | |
