This is a graphical comparison of party strengths in the 2nd session of the Scottish Parliament at the time of its dissolution in April 2007.
This is a list MSPs and party affiliations at the end of the session sorted by party, for a list of MSPs elected in the 2003 election see here. The changes table below records all changes in party affiliation during the session.
| Date | Constituency/Region | Gain | Loss | Note |
| May 07, 2003 | Ochil | | Presiding Officer | | SNP | George Reid is elected as the Presiding Officer and had to take voluntary suspension from the SNP. |
| July 10, 2004 | West of Scotland | | Independent | | SNP | Campbell Martin was expelled from the SNP after publicly criticizing the party leader. |
| January 10, 2005 | Mid Scotland and Fife | | | | Liberal Democrats | Keith Raffan resigned from Parliament, citing reasons of ill health, although it has been indicated that there were irregularities with his claims for expenses. |
| January 10, 2005 | Mid Scotland and Fife | | Liberal Democrats | | | Andrew Arbuckle replaces Keith Raffan as he was next on the Lib Dem regional list. |
| June 17, 2005 | South of Scotland | | | | Conservative | David Mundell resigned from Parliament as he was elected to the UK Parliament. |
| June 17, 2005 | South of Scotland | | Conservative | | | Derek Brownlee replaces David Mundell as he was next on the Conservative regional list. |
| September 05, 2005 | Glasgow Cathcart | | | | Labour | Mike Watson resigned from Parliament pending his conviction for arson. |
| September 05, 2005 | Glasgow Cathcart | | Labour | | | Charlie Gordon holds the seat vacated by Mike Watson at the by-election. |
| November 08, 2005 | Mid Scotland and Fife | | Independent | | Conservative | Brian Monteith is expelled from his party after briefing against his party leader David McLetchie. |
| March 21, 2006 | Moray | | | | SNP | Margaret Ewing dies in March 2006. |
| April 7, 2006 | North East Scotland | | | | SNP | Richard Lochhead resigned to contest the Moray by-election after Margaret Ewing's death. |
| April 7, 2006 | Highlands and Islands | | | | Conservative | Mary Scanlon resigned to contest the Moray by-election after Margaret Ewing's death. |
| April 19, 2006 | North East Scotland | | SNP | | | Maureen Watt replaces Richard Lochhead as she was next on the SNP regional list. |
| April 19, 2006 | Highlands and Islands | | Conservative | | | Dave Petrie replaces Mary Scanlon as he was next on the Conservative regional list. |
| May 3, 2005 | Moray | | SNP | | | Richard Lochhead holds the seat vacated by Margaret Ewing at the by-election |
| September 03, 2006 | Glasgow | | Solidarity | | Scottish Socialist | Tommy Sheridan resigned from the SSP and formed Solidarity. |
| September 03, 2006 | South of Scotland | | Solidarity | | Scottish Socialist | Rosemary Byrne resigned from the SSP and joined Solidarity. |
