Objectives Within current research, little is known about the long-term outcomes of craniosynostosis. A priority-setting exercise by UK charity Headlines Craniofacial Support identified 2 key questions in this area: (1) What are the long-term physical and psychological effects for individuals with syndromic and non-syndromic craniosynostosis? and (2) Are individuals with craniosynostosis likely to suffer from mental health difficulties, or are they more resilient? The aim of the current study was to conduct an initial investigation of these priority questions. Methods A comprehensive UK-wide survey consisting of 9 standardized psychological outcome measures and open-ended questions was distributed online. Thirty-six eligible adults (69.4% female) with a mean age of 30.8 years responded to the survey. Participants reported having single suture craniosynostosis (27.8%) or syndromic craniosynostosis (52.8%), with 19.4% being unsure of their diagnosis. Sample means were compared to published norms using independent samples t tests. Qualitative responses were analysed using inductive content analysis. Results Compared to the general population, participants reported significantly less favorable scores related to appearance concerns, attachment in adult relationships, anxiety, optimism, and resilience. Self-worth, depression, and social anxiety scores were similar to norms. Qualitative responses provided additional insight into participants’ satisfaction with appearance, physical health, medical treatment, employment, relationships, and recurrence risks. Few participants had accessed psychological support. Discussion This preliminary study illustrates the potential long-term implications for individuals with craniosynostosis. Improved treatment protocols are needed to address physical health concerns in adulthood, while dedicated psychological resources are necessary to promote emotional well-being, social confidence, and resilience.