We found little reliable evidence about clinical efficacy and safety of acetylcholinesterase inhibitors in non-Alzheimers dementia. We found one small controlled trial in people with vascular dementia. 2 Results were inconclusive because of the small size and lack of proper randomisation. The results of a recently completed RCT in people with vascular dementia are awaited. 3 We found one RCT in people with probable Lewy body dementia. 3 It found a non-significant trend in favour of rivastigmine over placebo for improving cognitive and behavioural function measured by NPI-4 and NPI-10 score. A significantly higher proportion of people treated with rivastigmine achieved 30% improvement in NPI-4 score compared with people given placebo. However, the clinical importance of this finding is unclear, because NPI scores have not been validated as a sensitive measure of change in people with dementia, or as a measure of response to dementia treatment. The trial found that although pre-existing parkinsonian symptoms did not worsen with rivastigmine, emergent tremor was noted as an adverse event in four rivastigmine-treated participants. 1 In conclusion, the available evidence suggests that acetylcholinesterase inhibitors may prove useful for treating cognitive and behavioural symptoms in people with non-Alzheimers dementia. However, we found insufficient evidence from studies to date of clinically important effects. Large RCTs are needed, examining outcomes that have been well validated as measures of response to therapy in dementia. Tolerability studies are needed, in particular to evaluate effects on parkinsonian symptoms in people with Lewy body dementia.