Objective: Neurofibromatosis Type I (NF1) is a single gene disorder associated with cognitive and behavioral deficits. While there is clear evidence for poorer social outcomes in NF1, the factors underlying reduced social function are not well understood. This study examined theory of mind (ToM) in children with NF1 and unaffected controls. Method: ToM was assessed in children with NF1 (n = 26) and unaffected controls (n = 36) aged 4–12 years using a nonverbal picture sequencing task. The task assessed understanding of ToM (unrealized goals, false belief, pretence, intention), while controlling for social script knowledge and physical cause-and-effect reasoning. Results: Children with NF1 made significantly more errors than unaffected controls on most ToM stories while demonstrating no difficulty sequencing physical cause-and-effect stories. Performance on the picture sequencing task was not related to lower intellectual function, symptoms of attention deficit-hyperactivity disorder (ADHD), or parent ratings of executive function. Conclusions: Results suggest a generalized ToM deficit in children with NF1 that appears to be independent of general cognitive abilities and ADHD symptoms. The study refines understanding of the clinical presentation of NF1 and identifies psychological constructs that may contribute to the higher prevalence of social dysfunction in children with NF1.