From the analysis of current scientific literature are still few studies on the relationship between personality disorders and borderline intellectual functioning, since the latter, without its own specificity, has always been considered as a kind of undefined zone between intellectual functioning medium and intellectual disabilities. Several studies have shown the presence of comorbidity of the personality disorders with BIF, emphasizing a higher frequency of Borderline Personality Disorder. BIF is considered a significant risk factor for the development of a broad spectrum of neuropsychiatric disorders, in particular in our observations ongoing since 2003, it assumes an important weight on the global functioning of patients with personality disorder as we have stated in the intervention SOPSI 2012. In detail, this study focuses on the relationship between BPD and BIF, noting the weight the latter on the social adaptability, job placement and creation of bonds of individuals with Borderline Personality Disorder. Patients included in this study were 52 (40 F and 12 M), of which 27 belonging to the first group had a borderline intellectual functioning in comorbidity with BPD and 25 individuals belonging to the second group with BPD without BIF. The results show that 33% of individuals included in the first group did not find a job working compared to 16% of the second group, showing further falls in attention and concentration, therefore, in the ability to anticipate and generalization, impacting strongly on the degree of adaptation to social life, while there are not significant differences in the ability to create emotional ties between the two groups.