Introduction: The traditional role of filial care for frail elderly in Chinese family, the responsibility of caring has typically fallen on women, especially on the daughters-in-law (DILs). To date, little is known about the impact of these DIL caregivers in Chinese society. This study aimed to explore the experiences of DILs on their caregiving involvement for parents-in-law (PILs) with dementia. Methods: A qualitative design of phenomenological methodology was used employing focus group discussion and participant observation with thirteen DILs. Participants were recruited from the psychiatric outpatient department of a hospital in Eastern Taiwan. Content analysis was used to identify themes. Results: Four main themes emerged: (1) care burden with filial obligation; (2) suffering alone; (3) feel powerless; and (4) adaptation. Discussion: The social expectations of DILs as primary family caregiver and lack of effective skill for caring PILs with dementia may lead DILs to feelings of vulnerability with associated physical problems and emotional strain. Family based interventions and educational programmes are recommended as a potential means to alleviate caregiver burden of the DILs .