The first two state tournaments were invitationals held at Drake Fieldhouse, featuring teams playing 6-on-6 basketball and involving 24 and 36 teams respectively. The tournament then rotated sites from 1922 to 1930, and varied in size from 8 to 20 teams from 1922 to 1924, before settling on a 4-team round-robin format from 1925 to 1930. Also beginning in 1925, qualification for state began to be determined by teams winning sectional and district tournaments across the state. In 1931, the field qualifying for the state tournament increased to 8 and the state tournament moved back to Drake Fieldhouse, where it would remain through the 1954 tournament. State was expanded to 16 teams in 1934, which was also the year the rules that would come to define 6-on-6 in Iowa were finalized. Due to travel restrictions during the second world war, only 8 teams took part in the 1943 state tournament, but otherwise the tournament continued following the same format through the 1978-79 season. 

With the growth in number of large schools playing girl's basketball, schools were classed for the first time in 1979-80, but the classes were used only in sectional and district tournaments to ensure schools of all sizes got a chance to make it to state. Four teams from each of 4 classes qualified for a single state tournament that year, though this was changed to 8 teams from each of two classes beginning in 1982. Until 1984-85, all state tournaments held involved teams playing 6-on-6 basketball. Starting that year, two tournaments would be held, one for teams playing 5-on-5 and another for teams playing 6-on-6. The format for the 6-on-6 tournament remained unchanged, while the initial 5-on-5 tournament involved four teams advancing to state from a field 26 that took part in district tournaments. As other schools switched to 5-on-5 in the late 1980s, the 5-on-5 state field was expanded to 8 in 1988-89. Dramatic change came in the 1993-94 school year, when the IGHSAU mandated all schools change to 5-on-5 girl's basketball, ending 6-on-6 play. Until that point, there were still far more schools offering 6-on-6 than 5-on-5. The same year, the tournament format was changed to have 8 teams qualify for state in each of 4 classes. The only change to the format since that time came in 2013 when, for the first time, a fifth class was added.