Despite a growing body of empirical data describing the discriminant and longitudinal validity of mania in older children, little research has been conducted investigating the presence of mania symptoms in preschool-aged children. This report describes three cases of preschool children (ages 3.6 to 5.2) who presented to a subspecialty mental health clinic manifesting age-adjusted mania-like symptoms. Developmental manifestations of DSM-IV mania symptoms described include grandiosity, hypersexuality, elation, racing thoughts, and decreased need for sleep. These symptoms have been shown to be highly specific to distinguish bipolar disorder from attention deficit hyperactivity disorder (ADHD) in older children. Possible manifestations of mood cycling are also described. Clinical observations, parental reports, and related family mental health history are reviewed.