Charles Catto trades
| Montreal Canadiens acquire | Date | St. Louis Blues acquire | ||
|---|---|---|---|---|
 | 1973 1st round pick (#8-Bob Gainey) | May 15, 1973 | 1973 1st round pick (#5-John Davidson) |  |
| 1973 4th round pick (#56-Alan Hangsleben) | 1973 3rd round pick (#48-Bob Gassoff) | |||
| 1975 1st round pick (#9-Robin Sadler) | ||||
| St. Louis Blues acquire | Date | Detroit Red Wings acquire | ||
|---|---|---|---|---|
| cash | May 15, 1973 | 1973 9th round pick (#135-Dennis O'Brien) |  |
| 1973 tenth round pick (#151-Kevin Neville) | ||||
| St. Louis Blues acquire | Date | New York Rangers acquire | ||
|---|---|---|---|---|
| Ab DeMarco Jr. | March 2, 1973 | Mike Murphy |  |
| Los Angeles Kings acquire | Date | St. Louis Blues acquire | ||
|---|---|---|---|---|
 | Frank St. Marseille | January 22, 1973 | Paul Curtis | |
| St. Louis Blues acquire | Date | Pittsburgh Penguins acquire | ||
|---|---|---|---|---|
| Joe Noris | January 8, 1973 | Jim Shires |  |
| St. Louis Blues acquire | Date | Philadelphia Flyers acquire | ||
|---|---|---|---|---|
| Brent Hughes | December 14, 1972 | Andre Dupont |  |
| Pierre Plante | 1973 3rd round pick (#40-Bob Stumpf) | |||
| St. Louis Blues acquire | Date | New York Rangers acquire | ||
|---|---|---|---|---|
| Andre Dupont | November 15, 1972 | Gene Carr | |
| Jack Egers | Wayne Connelly | |||
| Mike Murphy | Jim Lorentz | |||
| St. Louis Blues acquire | Date | New York Rangers acquire | ||
|---|---|---|---|---|
| Glen Sather | October 28, 1972 | Jack Egers | |
| Rene Villemure | ||||
| St. Louis Blues acquire | Date | Chicago Blackhawks acquire | ||
|---|---|---|---|---|
| Christian Bordeleau | September 15, 1972 | rights to John Garrett |  |
| St. Louis Blues acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
| cash | September 1, 1972 | Brian Lavender |  |
| St. Louis Blues acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
| cash | August 31, 1972 | Dave Pulkkinen | |
| Comment: Exact date unknown | ||||
| St. Louis Blues acquire | Date | New York Rangers acquire | ||
|---|---|---|---|---|
| cash | June 8, 1972 | 1972 9th round pick (#137-Pierre Archambault) | |