BACKGROUND: Using advance care planning (ACP) to anticipate future decisions can increase compliance with people's end-of-life wishes, decrease inappropriate life-sustaining treatment and reduce stress, anxiety and depression. Despite this, only a minority of older people engage in ACP, partly because care professionals lack knowledge of approaches towards ACP with older people and their families. OBJECTIVE: To explore older people's and their families' experiences with ACP in primary care. METHODS: We conducted qualitative, semi-structured, face-to-face interviews with 22 older people (aged >70 years, v/m: 11/11), with experience in ACP, and eight of their family members (aged 40-79 years, f/m: 7/1). Transcripts were inductively analysed using a grounded theory approach. RESULTS: We distinguished three main themes. (i) Openness and trust: Respondents were more open to ACP if they wanted to prevent specific future situations and less open if they lacked trust or had negative thoughts regarding general practitioners' (GPs') time for and interest in ACP. Engaging in ACP appeared to increase trust. (ii) Timing and topics: ACP was not initiated too early. Quality of ACP seemed to improve if respondents' views on their current life and future, a few specific future care scenarios and expectations and responsibilities regarding ACP were discussed. (iii) Roles of family: Quality of ACP appeared to improve if family was involved in ACP. CONCLUSIONS: Quality and accessibility of ACP may improve if GPs and nurses involve family, explain GPs' interest in ACP and discuss future situations older people may want to prevent, and views on their current life and future.