The first legislation in New Zealand providing for divorce was passed in 1867. It was identical with an English Act of 1857. The grounds were adultery by the wife, and adultery by the husband if accompanied by certain aggravating circumstances. No question of wider grounds arose, the English authorities having indicated that only a copy of their own legislation would be acceptable. In 1898 adultery by either party became a ground, and new grounds were introduced, including desertion for five years (three since 1919) and non-compliance with a decree for restitution of conjugal rights. This last ground led to abuses of procedure by those seeking a quick divorce. Since 1953 the non-compliance has had to be for three years, a change which has meant the virtual disuse of this ground.

Additional grounds were introduced in 1907. An important amendment in 1920 permitted divorce to be obtained, at the Court's discretion, by either party after three years' separation under a Court order or an agreement. The effect of this was, however, diminished in 1921, when the Court was required to refuse a decree if the respondent proved that the separation was due to the petitioner's wrongful conduct. The same restriction was imported into a 1953 provision which gave divorce after seven years of living apart without likelihood of reconciliation. This became the subject of some criticism and was removed by the Matrimonial Proceedings Act of 1963, which came into force on 1 January 1965.

Further changes were made in the 1963 Act and the grounds of divorce available after 1 January 1965 may be summarised as follows: adultery; artificial insemination of the respondent wife without the husband's consent; desertion for three years; habitual drunkenness for three years, with failure to support or neglect of domestic duties (as the case may be), or cruelty; conviction for murder or certain attempted murders; insanity and confinement for this reason for certain periods without likelihood of recovery; non-compliance for three years with a decree for restitution of conjugal rights; separation by Court order or agreement for three years; living apart for seven years without likelihood of reconciliation; conviction for certain offences of violence or sexual offences; rape, sodomy, or bestiality (wife's petition).

For some years in New Zealand there has been about one divorce for every 11 or 12 marriages. In 1960, 1,648 decrees absolute were granted. The most common ground is three years' separation, 875 decrees on this ground having been granted in 1960, compared with 403 for adultery and 224 for desertion. It is interesting that, although slightly more divorces are granted on wives' petitions than on husbands', almost twice as many divorces are granted to husbands for the wife's adultery as vice versa. This could reflect a continued attitude that a woman's adultery is more serious than a man's.

As elsewhere, a section of opinion in New Zealand regards marriage as incapable of dissolution except by death. The majority adopt the pragmatic view that divorce may be a lesser evil than the continuation of a marriage that is one only in name. Accepting divorce, the question arises whether it should be based on the commission of a serious matrimonial offence or on the breakdown of the marriage beyond reasonable hope of mending. The law of most Western countries that permit divorce (Australia and the Scandinavian countries are among the exceptions) remains based solely on the traditional “offence” approach. New Zealand, also, for the most part accepts this, but in its provision for divorce on the application of either party following prolonged separation it goes some distance towards recognising the breakdown principle. One weakness of the traditional approach is that the offence is often merely a symptom and not the underlying cause. This may be the fault of either or both in varying degrees.

Important ancillary questions often arise in divorce proceedings, notably the maintenance of the wife and the maintenance, welfare, and custody of the children. Occasionally there is a claim for damages for adultery, which can be sought in divorce proceedings but not otherwise. The Courts have always had a wide discretion in maintenance and custody matters. The 1963 Act gives them more extensive powers, particularly in relation to the matrimonial home and the welfare of children.