Softball, an offshoot of American baseball, was invented by Lewis Robler about 1898. The first game played in New Zealand, an exhibition between two company teams, was a curtain raiser to a rugby league match at the Wellington Winter Show Building in 1937. By December of that year there were 20 teams in the Wellington district. In 1938, after visits by Wellington teams, the game became established in Auckland, Wanganui, Palmerston North, Christchurch, and Levin. At first competitions were held only in the Wellington district; but as the game spread to other centres the need for some form of national governing body became apparent. Accordingly, on 11 January 1938, the New Zealand Softball Association was formed. This is affiliated with the American Softball Association and, in turn, with all the New Zealand provincial associations. The separate softball clubs are affiliated to their local or provincial associations. By August 1965 the competitive membership in New Zealand was: adults (men and women), 4,414; school children (in Saturday morning competitions), 3,523. Moreover, about 10,000 children take part in inter-school competitions every week.
Owing to limited finances and a dearth of contacts with similar bodies overseas, New Zealand softballers have had very little experience of international competition. Since 1949, however, a New Zealand women's side toured Australia with considerable success. In 1954 a Victorian men's team toured New Zealand and, seven years later, this was followed by an Australian women's team. A New Zealand women's team toured Australia in 1964. During this tour the New Zealand team gained fourth place in the World Series at Melbourne. The association is now endeavouring to arrange for an American club team to visit New Zealand. The results of these various international tours are as follows:
| 1949 | New Zealand (women) in Australia: 3 tests, won 1, lost 2. |
| 1954 | Victoria (men) in New Zealand: no tests, 12 games, won 7, lost 5. |
| 1961 | Australia (women) in New Zealand: 3 tests, won 2, lost 1; 13 other games, won 12, lost 1. |
| 1964 | New Zealand (women) in Australia: no tests, 17 games, won 14, lost 3. |
| 1964 | New Zealand (women); World Series: 11 games, won 4, lost 7. |
The first interprovincial tournament was held at Wellington in 1939. The trophies competed for are: the John Lennon Trophy (for men's club teams); the Beatty Cup (for men's interprovincial teams); the Dustin Cup (for women's club teams); and the Bensell Cup (for women's interprovincial teams). In addition, there are annual North versus South matches (Headifen Memorial Trophy since 1962) and a similar contest for women's teams. Results have been:
| (Since 1962, the Headifen Memorial Trophy) | |
| 1948 | North 9, South 2 |
| 1949 | South 6, North 3 |
| 1950 | North 15, South 0 |
| 1951 | No game |
| 1952 | South 4, North 3 |
| 1953 | North 22, South 6 |
| 1954 | North 11, South 1 |
| 1955 | North 15, South 8 |
| 1956 | No game |
| 1957 | North 4, South 2 |
| 1958 | No game |
| 1959 | North 6, South 0 |
| 1960 | North 2, South 0 |
| 1961 | No game |
| 1962 | North 3, South 0 |
| 1963 | North 2, South 1 |
| 1964 | North 5, South 4 |
| 1965 | North 1, South 0 |
| 1940 | Jenkins Gym (Wellington) |
| 1941 | Miramar (Wellington) |
| 1942–44 | No play |
| 1945 | Broadway (Wellington) |
| 1946 | Jenkins Gym (Wellington) |
| 1947 | No play |
| 1948 | Broadway (Wellington) |
| 1949 | No play |
| 1950 | Eden (Auckland) |
| 1951 | Eden (Auckland) |
| 1952 | Miramar (Wellington) |
| 1953 | Broadway (Wellington) |
| 1954 | Cardinals (Hutt) |
| 1955 | Jenkins Gym (Wellington) |
| 1956 | Cardinals (Hutt) |
| 1957 | Miramar (Wellington) |
| 1958 | Broadway (Wellington) |
| 1959 | Broadway (Wellington) |
| 1960 | Railways (Wellington) |
| 1961 | Miramar (Wellington) |
| 1962 | Railways (Hutt Valley) |
| 1963 | Railways (Hutt Valley) |
| 1964 | Railways (Hutt Valley) |
| 1965 | Railways (Hutt Valley) |