Borderline intellectual functioning (BIF) is characterized by heterogeneous cognitive difficulties, with an Intelligence Quotient (IQ) between 70-85 points, and a failure to meet the developmental and sociocultural standards for personal independence and social responsibility required in daily life. The fact that people with BIF still remain a marginal clinical category, with no ad hoc diagnostic and therapeutic approaches, has stimulated the present research. Our goal was to study BIF children investigating the development of Theory of Mind (ToM) as a pillar of social competence. Children with BIF (N=28, 16 male/12 female, mean age 9.46 ± 1.26 years) and children with typical development (TD) (N=31, 17 male/14 female; mean age 8.94 years ± 0.99) underwent a neurocognitive assessment and a ToM assessment. Children with BIF showed a significant lower performance across all the levels of ToM development investigated compared to the control group, and a correlation between executive functions and the advanced levels of ToM reasoning. These results constitute a first step in the direction of defining the clinical profile of BIF concerning ToM development, opening the way to future interventions in order to support the developmental evolution of this people in an adaptive direction.