For many patients with bipolar disorder there is a long delay between the onset of illness and receiving a diagnosis and the initiation of treatment. This may have an adverse effect on the clinical outcome. Early intervention in bipolar disorder has received less attention than in schizophrenia, and there are relatively few specialist services in this area. This article reviews the literature on the early detection of bipolar disorder and on the effectiveness of pharmacological, psychological and psychosocial interventions in the early phase of the disorder.