Memory problems are the most common cognitive deficits in dementia. In order to help these patients with their everyday activities and to increase their quality of life, a number of memory aids have been developed. This paper focuses on the efficacy and the applicability of three different types of external memory aids. The findings suggest that environmental adjustment is an easy and low-priced method. It is beneficial even for patients in the most severe stages of dementia, since only a limited amount of training is necessary. The non-electronic aids are also relatively cheap and easy to learn. The electronic aids are more expensive and, at this point, only a few studies have investigated the efficacy of this memory aid on the memory problems of patients with dementia. However, most published studies only investigated small samples. Hence, the current results should be interpreted with caution.