Abstract Study question What are the clinical characteristics and medical outcomes of cross-border surrogacy (CBS) arrangements? Summary answer CBS practices commonly involve anonymously donated oocytes and multiple embryo transfers which can adversely impact the psychological and physical welfare of the children born. What is known already Intended parents may seek CBS when surrogacy in their home country is prohibited or when access is restricted to heterosexual couples, or when they cannot find a surrogate in their home country. Standards of clinical care can differ between the parents' home country and the CBS destination. Surrogacy is generally unregulated in CBS destinations, making it difficult to monitor clinical practices and the outcomes for the children born. In Australia, where this study is set, anonymous gamete donation and multiple embryo transfers for patients engaged in surrogacy is prohibited. The rate of twin surrogacy deliveries is 2.2%. Study design, size, duration This cross-sectional study collected data through an online, anonymous survey open between April and November 2021. Participants/materials, setting, methods A survey with predominantly fixed-choice questions was developed and informed by the authors’ prior research, the literature, and one author’s experience of surrogacy and surrogacy advocacy. Questions were refined through an iterative process involving consultation with parents through surrogacy. Australian parents through surrogacy were eligible to participate and the study was advertised to personal contacts, members of a surrogacy non-profit organisation and members of a surrogacy related Facebook group. Data were analysed descriptively. Main results and the role of chance One hundred and eight Australian parents through CBS completed the survey. Surrogacy was undertaken in twelve destinations, with approximately half of respondents completing surrogacy in the United States of America (34%, n = 37) or Canada (17%, n = 18). Almost all respondents reported the pregnancy was a result of an embryo transfer (92%, n = 98) and not artificial insemination (8%, n = 10). Of those reporting embryo transfer, 41% reported the transfer of multiple embryos (n = 40) and 79% reported the use of donor oocytes (n = 77). Of the respondents that used donor oocytes, almost half were from an anonymous donor (47%, n = 36) and all but one noted their intent to disclose the use of donor oocytes to their child (97%, n = 76). Pregnancy or birth complications were reported by 29% of respondents (n = 31). There were 12 twin births (11%), 22 preterm births (20%) and 24 births requiring neonatal intensive care (22%). The median time spent in the neonatal intensive care unit was 6 days (range 1-60). All but one twin birth arose from pregnancies resulting from a multiple embryo transfer and the majority were preterm (75%, n = 9) and required neonatal intensive care (59%, n = 7). Limitations, reasons for caution It is not known if those who completed the survey are representative of all parents through CBS. However, the respondents’ sociodemographic characteristics and motivations for surrogacy were similar to those in previously conducted studies, both within Australia and internationally. Wider implications of the findings The welfare of children born through surrogacy can be protected by addressing the barriers to undertaking surrogacy domestically and thereby reducing the number of people crossing borders, and by promoting identity release or known donation and single embryo transfer as best practice in surrogacy internationally. Trial registration number Not applicable