Objectives: The aim of this study was to explore nurses' experience of strain in dementia care. Method: Focus groups were held with 35 nurses in Sweden, Australia and UK, who care for people with dementia. The discussions were tape-recorded and analysed using qualitative content analysis. Results: The nurses described the complexity of their situation and referred to environmental factors such as 'the system', community attitudes, other staff, residents' family members and also their own family. With regard to caring for people with dementia, three main sources of strain could be identified: Being unable to reach; Trying to protect; and Having to balance competing needs. Conclusion: The nurses' experience could be understood as a desire to do the best for the people in their care by trying to alleviate their suffering and enhance their quality of life. When they did not have the resources, opportunity or ability to do this, it caused strain.