The purpose of this prospective, naturalistic study was to examine the relationships between suicide attempts and contemporaneous psychiatric disorders, and developmental changes in these relationships from adolescence to young adulthood. The sample consisted of 180 adolescents, 12-19 years of age at hospitalization, repeatedly assessed for up to 13 years (n = 1,825 assessments). Semistructured psychiatric diagnostic instruments were administered at repeated assessments to assess psychiatric disorders and suicide attempts. After controlling for demographic variables and prehospitalization suicide attempts, most contemporaneous psychiatric disorders (major depressive disorder [MDD], dysthymic disorder, generalized anxiety disorder [GAD], panic disorder, attention-deficit/hyperactivity disorder [AD/HD], conduct disorder, and substance use disorder [SUD]) were related to increased risk of attempts. The relationship between suicide attempts and MDD, GAD, AD/HD, and SUD strengthened as participants got older. MDD, dysthymic disorder, GAD, and panic disorder were more commonly associated with repeat than 1st-time suicide attempts. In sum, most major psychiatric disorders are associated with increased risk for suicide attempts, but the strength of the relationships between these disorders and attempts changes over the course of development. (Contains 3 tables.)