Approximately 40% of patients with bipolar disorder experience mixed episodes, defined as a manic state with depressive features, or manic symptoms in a patient with bipolar depression. Compared with bipolar patients without mixed features, patients with bipolar mixed states generally have more severe symptomatology, more lifetime episodes of illness, worse clinical outcomes and higher rates of comorbidities, and thus present a significant clinical challenge. Most clinical trials have investigated second-generation neuroleptic monotherapy, monotherapy with anticonvulsants or lithium, combination therapy, and electroconvulsive therapy (ECT). Neuroleptic drugs are often used alone or in combination with anticonvulsants or lithium for preventive treatment, and ECT is an effective treatment for mixed manic episodes in situations where medication fails or cannot be used. Common antidepressants have been shown to worsen mania symptoms during mixed episodes without necessarily improving depressive symptoms; thus, they are not recommended during mixed episodes. A greater understanding of pathophysiological processes in bipolar disorder is now required to provide a more accurate diagnosis and new personalised treatment approaches. Targeted, specific treatments developed through a greater understanding of bipolar disorder pathophysiology, capable of affecting the underlying disease processes, could well prove to be more effective, faster acting, and better tolerated than existing therapies, therefore providing better outcomes for individuals affected by bipolar disorder. Until such time as targeted agents are available, second-generation neuroleptics are emerging as the treatment of choice in the management of mixed states in bipolar disorder.