Emerging support for the roles of both early trauma and family environment in the development of dissociative symptomatology is complicated by the frequent co-occurrence of dysfunctional family environments and childhood maltreatment. The present investigation prospectively examined the influence of family environment on dissociative symptom course in 82 youths (8–18 years) who experienced accidental injury. The primary caretaker reported on six-week family environment (including family cohesion and adaptability) and on youth symptoms of dissociation prior to injury at six weeks and at six months; dissociation prior to injury was assessed via retrospective parent account at the six-week timepoint. Adolescents (aged 11–18) also reported on their own dissociative symptoms at six weeks. Latent growth modeling indicated that youth in more cohesive family environments evidenced decreased symptoms of dissociation at the six-week intercept (z = –2.80). Furthermore, parent income was negatively related to symptoms of dissociation at intercept (z = –1.96) and parent education was associated with a decrease in youth dissociation symptoms over time (z = –2.57). The present findings provide support for the importance of acute family environment in pediatric post-injury adjustment and further highlight the importance of parent resources, including income and education, in post-injury adjustment.