Background Complementary therapy has receivedgreatinterestwithin the fieldofdementia treatment andthe use of aromatherapy andessential oils is increasing. In a growing population where the majority of patients are treated by US Food and Drug Administration (FDA)-approved drugs, the eCicacy of treatment is short term and accompanied by negative side eCects. Utilisation of complimentary therapies in dementia care settings presents as one of few options that are attractive to practitioners and families as patients oJen have reduced insight and ability to verbally communicate adverse reactions. Amongst the most distressing features of dementia are the behavioural and psychological symptoms. Addressing this facet has received particular interest in aromatherapy trials, with a shiJ in focus from reducing cognitive dysfunction to the reduction of behavioural and psychological symptoms in dementia. Objectives To assess the eCicacy of aromatherapy as an intervention for people with dementia. Search methods ALOIS,theCochraneDementia andCognitive ImprovementGroup SpecializedRegister,was searched on 26November 2012 and 20 January 2013 using the terms: aromatherapy, lemon, lavender, rose, aroma, alternative therapies, complementary therapies, essential oils. Selection criteria All relevant randomised controlled trials were considered. A minimum length of a trial and requirements for follow-up were not included, and participants in included studies had a diagnosis of dementia of any type and severity. The review considered all trials using fragrance from plants defined as aromatherapy as an intervention with people with dementia and all relevant outcomes were considered. Data collection and analysis Titles and abstracts extracted by the searches were screened for their eligibility for potential inclusion in the review. For Burns 2011, continuous outcomes were estimated as the mean diCerence between groups and its 95% confidence interval using a fixed-eCect model. For Ballard 2002, analysis of co-variance was used for all outcomes, with the nursing home being treated as a random eCect. Main results Seven studies with 428 participants were included in this review; only two of these had published usable results. Individual patient data were obtained from one trial(Ballard 2002) and additional analyses performed. The additional analyses conducted using individual patient data from Ballard 2002 revealed a statistically significant treatment eCect in favour of the aromatherapy intervention on measures of agitation (n = 71, MD -11.1, 95% CI -19.9 to -2.2) and behavioural symptoms (n = 71, MD -15.8, 95% CI -24.4 to -7.2). Burns 2011, however,found no diCerence in agitation (n = 63, MD 0.00, 95% CI -1.36 to 1.36), behavioural symptoms (n = 63, MD 2.80, 95% CI -5.84 to 11.44), activities of daily living (n = 63, MD -0.50, 95% CI -1.79 to 0.79) and quality of life (n = 63, MD 19.00, 95% CI -23.12 to 61.12). Burns 2011 and Fu 2013 found no diCerence in adverse eCects (n = 124, RR 0.97, 95% CI 0.15 to 6.46) when aromatherapy was compared to placebo. Authors' conclusions The benefits of aromatherapy for people with dementia are equivocal from the seven trials included in this review. It is important to note there were several methodological diCiculties with the included studies. More well-designed, large-scale randomised controlled trials are needed before clear conclusions can be drawn regarding the eCectiveness of aromatherapy for dementia. Additionally, several issues need to be addressed, such as whether diCerent aromatherapy interventions are comparable and the possibility that outcomes may vary for diCerent types of dementia.