The Pending Home Sales Index rose 3.6 percent to 94.6 from an upwardly revised reading of 91.3 in May, and is 6.7 percent higher than in June 2008.
The last time there were five consecutive monthly gains was July 2003.
"Historically low mortgage interest rates, affordable home prices and large selection are encouraging buyers who've been on the sidelines. Activity has been consistently much stronger for lower priced homes," said Lawrence Yun, NAR chief economist.
Pending home sales were higher in all four regions than last month, and only the west experienced a decrease from a year ago.
"Hopefully, in the months ahead, we'll see an even closer relationship between contract activity and closed transactions," said NAR president Charles McMillan.