The validity of diagnosis of personality disorder in an individual with intellectual and developmental disabilities (IDD) has been debated. The scientific literature of these diagnoses will be discussed with Antisocial personality disorder (AsPD) and borderline personality disorder (BPD) having most scientific research. Common symptoms associated with personality disorder are longstanding patterns of interpersonal difficulties, problems with emotional regulation, and deviates markedly from norms and experiences of the individual’s culture (DSM-5-TR). DM-ID-2 adapts DSM-5 criteria for people with IDD, thus placing personality disorders within the context of IDD culture. Treatment options will be discussed as well as practical suggestions for clinicians and direct care professions.