OBJECTIVE: The aim of this article is to review the major instruments proposed for screening for bipolar disorder among clinical or general, adult or paediatric populations. They were developed in order to improve the detection of this illness which, far too often, remains unrecognized. Several of these screening instruments are already translated into several languages and validated. METHODOLOGY: A systematic review of the literature published on this topic up to July 2007 was carried out, using the main electronic data base (Medline). The keywords employed included bipolar disorder, screening, questionnaire, diagnosis and early recognition. RESULTS: The studies reported here examine whether screening instruments perform similarly in various clinical and non-clinical samples. Different forms of the same questionnaire (like self-report or parent report used in paediatric samples) are sometimes compared, usually showing that parent reports supersede the adolescent self-report form. This is namely the case for the Mood Disorder Questionnaire (MDQ) which is a brief and widely tested tool, available both in adult and adolescent versions. The MDQ exhibits good psychometric properties in relation to sensitivity and specificity in adult psychiatric samples, but these are more limited in the general population. Moreover, it yields better sensitivity for BP type I than for other bipolar subtypes. This is also true for other screening instruments like the hypomania check list (HCL-32). In order to optimize the sensitivity for bipolar II disorders, proposals for changing the MDQ screening algorithm have been tested. DISCUSSION: Even though it does not replace a thorough clinical interview, the use of screening tools for bipolar disorder is widely advocated. We discuss the need for clinicians to rely upon instruments allowing for a rapid and economically feasible identification of this disorder. Involving family members in the evaluation process may also increase the rate of recognition. More studies are still required in order to improve diagnostic efficiency of the screening instruments.