The Postseason Women's National Invitation Tournament began in 1998 with 16 teams playing for a postseason crown. The event has undergone four expansions throughout which its mission has remained the same: To give deserving teams a quality opportunity to play exciting games for a postseason title.

Following the inaugural year, the field doubled to 32 teams and remained that way until 2006 when a renewed commitment was made to schools. The WNIT expanded to a 40-team field to give spots to teams that won their regular-season conference title but did not win their conference tournament and therefore were excluded from the NCAA Tournament.

The WNIT furthered that commitment to conferences in 2007, when it expanded to 48 teams and awarded an automatic berth to each conference. The number of at-large berths remained at 17 until 2010, when the WNIT felt that the level of women's basketball warranted an expansion to the 64-team field.