Women's reasons for returning to work after childbearing are complex, often including a mix of financial and other reasons related to their preferences, choices and constraints. Various qualitative studies have explored this decision-making process, but the topic has less-often been explored using quantitative analyses of large samples. This paper uses a quantitative approach, considering women's reasons for returning to work, and analysing how these reasons for return to work vary with factors such as women's timing of return to work, what types of jobs they had previously worked in (or returned to) and what type of leave they used. This enables an examination of which women feel more constrained in their labour market options - returning to work sooner than preferred - also informing why they returned to work sooner than preferred. This analysis is based on the 2005 Parental Leave in Australia Survey, a survey nested in the Wave 1.5 collection of the Longitudinal Study of Australian Children (LSAC). The study children of this cohort were aged at least 15 months at this time, at which time 56 per cent of mothers had returned to work.