Bipolar disorder is an important and serious mental illness associated with significant morbidity and mortality. However, unfortunately, the evidence base regarding treatment is less than satisfactory. In such circumstances clinicians often resort to reputable sets of guidelines. A number of these currently exist; in the United Kingdom the most prominent being that produced by the British Association of Psychopharmacology (BAP). This paper reviews the methodology of this guideline and its recommendations regarding the long-term treatment of bipolar disorder and compares this with guidelines produced by the American Psychiatric Association (APA), the Canadian Network for Mood and Anxiety Treatments (CANMAT) and the Texas Implementation of Medication Algorithms (TIMA) for bipolar I disorder. It is concluded that the BAP guidelines continue to be a reasonable set of recommendations, though there are new data available since their publication. All the guidelines reviewed place lithium and valproate at the top of the list of options for long-term treatment. There is a trend to increasingly recognize atypical antipsychotics, particularly olanzapine, as an additional alternative and an increasing prominence of lamotrigine for prevention of depressive relapses. All other treatment options currently have an extremely limited evidence base and do not feature consistently in the published guidelines.