New York Islanders trades
| Florida Panthers acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
 | rights to Jiri Dopita | June 26, 1999 | 1999 5th round pick (#140-Adam Johnson) |  |
| Dallas Stars acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
 | 1999 2nd round pick (#32-Michael Ryan) | June 26, 1999 | 1999 1st round pick (#28-Kristian Kudroc) | |
| 1999 3rd round pick (#96-Mattias Tjarnqvist) | ||||
| Colorado Avalanche acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
 | 2000 9th round pick (#266-Sean Kotary) | June 26, 1999 | 1999 9th round pick (#268-Tyler Scott) | |
| Dallas Stars acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
| Warren Luhning | June 25, 1999 | 1999 3rd round pick (#96-Mattias Tjarnqvist) | |
| Los Angeles Kings acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
 | Marcel Cousineau | June 19, 1999 | Mathieu Biron | |
| Zigmund Palffy | Josh Green | |||
| Bryan Smolinski | Olli Jokinen | |||
| 1999 4th round pick (#125-Daniel Johansson) | 1999 1st round pick (#8-Taylor Pyatt) | |||
| Montreal Canadiens acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
 | Trevor Linden | May 29, 1999 | 1999 1st round pick (#10-Branislav Mezei) | |
| Nashville Predators acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
 | Andy Berenzweig | April 13, 1999 | 1999 4th round pick (#102-Johan Halvardsson) | |
| New Jersey Devils acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
 | Sergei Nemchinov | March 22, 1999 | 1999 4th round pick (#125-Daniel Johansson) | |
| Arizona Coyotes acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
 | Robert Reichel | March 20, 1999 | Brad Isbister | |
| 1999 3rd round pick (#71-Jason Jaspers) | 1999 3rd round pick (#87-Brian Collins) | |||
| 1999 4th round pick (#123-Preston Mizzi) | ||||
| Edmonton Oilers acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
 | Tommy Salo | March 20, 1999 | Mats Lindgren | |
| 1999 8th round pick (#228-Radek Martinek) | ||||
| New York Islanders acquire | Date | Ottawa Senators acquire | ||
|---|---|---|---|---|
| 1999 4th round pick (#123-Preston Mizzi) | March 20, 1999 | Ted Donato |  |
| New York Islanders acquire | Date | Ottawa Senators acquire | ||
|---|---|---|---|---|
| cash | March 19, 1999 | Chris Luongo | |
| Montreal Canadiens acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
| Scott Lachance | March 9, 1999 | 1999 3rd round pick (#78-Mattias Weinhandl) | |
| Tampa Bay Lightning acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
 | 1999 6th round pick (#182-Fedor Fedorov) | January 18, 1999 | Craig Janney | |
| Toronto Maple Leafs acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
 | Bryan Berard | January 9, 1999 | Felix Potvin | |
| 1999 6th round pick (#161-Jan Socher) | 1999 6th round pick (#182-Fedor Fedorov) | |||
| Colorado Avalanche acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
| Michael Gaul | December 15, 1998 | Ted Crowley | |
| Boston Bruins acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
 | Ken Belanger | November 7, 1998 | Ted Donato | |
| Washington Capitals acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
 | Tom Chorske | October 16, 1998 | 1999 6th round pick (#163-Bjorn Melin) | |
| 1999 8th round pick (#219-Maxim Orlov) | ||||
| Colorado Avalanche acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
| cash | September 10, 1998 | Nick Beaudoin | |
| Philadelphia Flyers acquire | Date | New York Islanders acquire | ||
|---|---|---|---|---|
 | 2000 6th round pick (#172-Scott Selig) | August 25, 1998 | rights to Raymond Giroux | |