- Aug 5 Thoroughbred trainer Dale Baird wins his 5,000th career race with Stuffed Johnnie at Mountaineer Park; second to reach milestone behind Jack Van Berg
- Aug 6 Rich Gossage becomes the second player in MLB history to record 300 career saves as Cubs beat Phillies, 7-4
- Aug 7 Future Hall of Fame jockey Eddie Delahoussaye wins his 4,000th career race aboard 2-year-old filly Fawn and Hahn in the 4th race at Del Mar
- Aug 8 Cubs & Phillies attempt to play 1st night game ever at Wrigley Field but are rained out in 4th inning with Chicago leading, 3-1
- Aug 8 Minnesota Twins pull 2nd triple-play of year in 6-2 win over Cleveland
US Senior Golf Open
Aug 8 US Senior Open Men's Golf, Medinah CC: Gary Player of South Africa wins by 2 strokes over New Zealander Bob Charles in an 18-hole playoff; his second straight US Senior title
- Aug 9 Cubs beat Mets 6-4 in their 1st official night game at Wrigley Field
NHL Trade
Aug 9 Edmonton Oilers trade Wayne Gretzky to LA Kings for $15-$20 millions
World Record
Aug 10 Matt Biondi swims world record 100m free style (48.42 sec)
Sports History
Aug 11 225 at bats after #299, Met Gary Carter is 59th to hit 300th HR
- Aug 12 Boston Red Sox beat Tigers 9-4 for AL record 23rd consecutive win at home
- Aug 13 Boston Red Sox win AL record 24 straight home games
- Aug 13 US beats Jamaica 5-1 in 2nd round of 1990 world soccer cup
- Aug 14 PGA Championship Men's Golf, Oak Tree GC: Jeff Sluman wins his only major title by 3 shots from Paul Azinger
Sports History
Aug 19 NY Rangers sign ex-Canadien great Guy LaFleur out of retirement
- Aug 20 Yordanka Donkova of Bulgaria sets 100m hurdle woman's record (12.21)
Sports History
Aug 23 Mike Tyson & Mitch Green brawl at 4 A.M. in Harlem, NYC
Sports History
Aug 27 Dodger Tommy Lasorda wins 1,000th game as manager tops Philadelphia, 4-2