This discussion paper describes the characteristics and life styles of single adults in Australia. Recent changes in sociological theory concerning marriage, family life, and single life are noted in the introduction, followed by a description of historical and demographic trends. Different categories of single adults (i.e., never married, widowed, permanently separated, divorced, and single parents), and types of single adult interpersonal relationships (i.e., free floating, open couple, closed couple, and de facto marriage), are described. The concept of the singles career is looked at in terms of these relationships and in adult accommodation to the single state. Positive and negative factors influencing adults' decision to remain single are noted, and negative stereotypes of singles and problematic aspects of being single are examined. Factors influencing future marital trends are highlighted. A 46-item bibliography is included in the paper. (WAS)