The dataset was generated during a cross sectional survey conducted in May-June 2020, aimed at exploring the impact of COVID 19 pandemic on mental health of caregivers of people with dementia. Data come from a sample of 571 caregivers of people with dementia living in Italy and Southern Switzerland. We registered socio-demographic characteristics, and information about the relationship with the care recipient, dementia subtype, care inputs from others, and the need of care of the person with dementia. We measured caregiver burden with the Zarit Burden Interview (ZBI), psychological distress with the Depression, Anxiety and Stress Scale (DASS-21), and perceived isolation with the 3-item UCLA Loneliness Scale (UCLALS3).