Background Cost-of-illness studies in palliative care are of growing interest in health economics. There is no standard methodology to capture direct and non-direct healthcare and non-healthcare expenses incurred by health services, patients and their caregivers in the course of the ambulatory palliative care process. Objective We aimed to describe the type of healthcare and non-healthcare expenses incurred by patients with cancer and non-cancer patients and their caregivers for palliative care in ambulatory-based settings and the methodology used to capture the data. Methods We conducted a systematic review of studies on the costs of ambulatory-based palliative care in patients with cancer (breast, lung, colorectal) and non-cancer conditions (chronic heart failure, chronic obstructive pulmonary disease, dementia) found in six bibliographic databases (PubMed, EMBASE [via Ovid], Cochrane Database of Systematic Reviews, EconLit,