Dementia with Lewy bodies (DLB) is a common type of dementia. The core clinical symptoms are visual hallucinations, fluctuating cognition with pronounced variations in attention, REM sleep behaviour disorder and parkinsonism. Early diagnosis and differentiation from Alzheimer's disease can be challenging, especially when the core clinical symptoms are modest or only partly present. In this case report, we describe two patients, who had unexplained loss of consciousness and visual hallucinations, which were the early signs of DLB in absence of parkinsonism.