BACKGROUND Antisocial personality disorder (AsPD) is associated with a wide range of disturbance including persistent rule-breaking, criminality, substance misuse, unemployment, homelessness and relationship difficulties. OBJECTIVE To evaluate the potential beneficial and adverse effects of pharmacological interventions for people with AsPD. METHODS We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2009, Issue 3), MEDLINE (1950 to September 2009), EMBASE (1980 to 2009, week 37), CINAHL (1982 to September 2009), PsycINFO (1872 to September 2009) , ASSIA (1987 to September 2009) , BIOSIS (1985 to September 2009), COPAC (September 2009), National Criminal Justice Reference Service Abstracts (1970 to July 2008), Sociological Abstracts (1963 to September 2009), ISI-Proceedings (1981 to September 2009), Science Citation Index (1981 to September 2009), Social Science Citation Index (1981 to September 2009), SIGLE (1980 to April 2006), Dissertation Abstracts (September 2009), ZETOC (September 2009) and the metaRegister of Controlled Trials (September 2009). METHODS Controlled trials in which participants with AsPD were randomly allocated to a pharmacological intervention and a placebo control condition. Two trials comparing one drug against another without a placebo control are reported separately. METHODS Three review authors independently selected studies. Two review authors independently extracted data. We calculated mean differences, with odds ratios for dichotomous data. RESULTS Eight studies met the inclusion criteria involving 394 participants with AsPD. Data were available from four studies involving 274 participants with AsPD. No study set out to recruit participants solely on the basis of having AsPD, and in only one study was the sample entirely of AsPD participants. Eight different drugs were examined in eight studies. Study quality was relatively poor. Inadequate reporting meant the data available were generally insufficient to allow any independent statistical analysis. The findings are limited to descriptive summaries based on analyses carried out and reported by the trial investigators. All the available data were derived from unreplicated single reports. Only three drugs (nortriptyline, bromocriptine, phenytoin) were effective compared to placebo in terms of improvement in at least one outcome. Nortriptyline was reported in one study as superior for men with alcohol dependency on mean number of drinking days and on alcohol dependence, but not for severity of alcohol misuse or on the patient's or clinician's rating of drinking. In the same study, both nortriptyline and bromocriptine were reported as superior to placebo on anxiety on one scale but not on another. In one study, phenytoin was reported as superior to placebo on the frequency and intensity of aggressive acts in male prisoners with impulsive (but not premeditated) aggression. In the remaining two studies, both amantadine and desipramine were not superior to placebo for adults with opioid and cocaine dependence, and desipramine was not superior to placebo for men with cocaine dependence. CONCLUSIONS The body of evidence summarised in this review is insufficient to allow any conclusion to be drawn about the use of pharmacological interventions in the treatment of antisocial personality disorder.