The objective of this paper is to compare the singulate mean age at union (smau) and singulate mean age at marriage (smam) of Brazilian women in twenty-seven states in 2000 and 2010. It explores associations between these mean ages and three variables: availability of partners of the opposite sex, feasibility of marriage and changing appreciation of marriage as a value. The mean age at union (smau) is more associated with the availability of partners. On the other hand, smam is more associated with socioeconomic variables than smau. Socioeconomic disadvantages are more related to smam more than smau. It is very hard to capture changes in the appreciation of marriage as a value, because the available variables are not ideal for this. However, the sex ratio of the employed population and of males and females who have completed tertiary education in the geographic areas analyzed are used as proxies of differences between these two values.1019107125