The role and responsibilities of next-of-kin carers are significant, filling several years of their lives and causing them to experience a burden of care. This study was conducted to investigate the burden of next-of-kin carers for dementia sufferers in Slovakia. Data were compiled via the Relatives’ Stress Scale (RSS) screening instrument through a survey of 112 primary next-of-kin carers and analysed using the statistical tests of descriptive statistics, means, scores and significance differences (Wilcoxon test). This is one of the few scales which provides: (a) specific measures of caregiver stress, and (b) is standardised for a population of informal carers in the home environment. The profiles of Slovak next-of-kin carers were identified with statistically significant characteristics (gender, age of carers). The study identified a high level of caregiving stress (82.15%), and selected factors were found to be significant in all burden dimensions: emotional stress (p = 0.001), social stress (p = 0.003), and negative feelings (p = 0.002). The results emphasise the need for coordination of healthcare and social services, possibly by expanding the network of social support groups, operating a counselling hotline/chat, and introducing national educational programmes for the next-of-kin carers of dementia sufferers. The results are also a source of reference for the umbrella organisation ‘the Slovak Alzheimer’s Society’ to access when implementing changes at a national level.