One of the most significant demographic trends in Indonesia over the last few decades has been the transformation of the institution of marriage. The most obvious change occurred in 1974 with the promulgation of a new Marriage Law which set new minimum ages of marriages, changed the procedures for registering a marriage, and altered the relative rights of men and women to contract and dissolve unions. These changes are reflected in the consistent rise in the average age at marriage of women from the late teens to the early 20s. Another way of looking at the trends in marital status is to examine the proportions of women who are recorded as being in each status at the time of the survey. The broad patterns are that the proportion of women in the child bearing age groups who are single at any given time has risen substantially over the period. This has been offset to some degree by declines in the proportions divorced and widowed, but the net effect has been a fall in the proportions of women who are currently married. This has had a dampening effect on fertility, and is, with rising contraceptive use, one of the major explanations for the recent falls in birth rates in the country. The changing patterns of marriage in Indonesia are important as indicators of the pace of social and economic changes in the country, as well as factors in a major cultural transformation which is proceeding in every area of the far-flung archipelago.