Objectives: This study aimed to quantify the breast support wearing and purchasing habits of young women and to assess factors that affect their sports bra usage during physical activity. Design: Study results were obtained from a self-administered mail survey, which was posted to participants after gaining their verbal consent via random telephone recruitment. Participants: 413 women aged 20 to 35 years were recruited from New South Wales, Australia. Results: From the returned (65%) surveys only 41% of respondents currently wore an encapsulating sports bra during physical activity, primarily due to a lack of awareness of the importance of good breast support during physical activity. Bra size was a predictor of sports bra usage, whereby participants with large breasts were more than twice as likely to wear a sports bra as their smaller-breasted counterparts. Conclusions: It was concluded that, although encapsulating sports bras have been shown to effectively reduce breast motion and associated exercise-induced breast discomfort, these bras were not the breast support option most commonly chosen by young women during physical activity. It is recommended that all women, irrespective of breast size, be educated on the importance of wearing a well-fitted and supportive bra during physical activity to decrease excessive strain on breast tissue structures and related breast discomfort.