Objective Knowledge is limited about the standardised instruments used to collect resource use and quality of life data alongside trials of dementia interventions. This review aimed to identify the trials using such instruments in order to guide the design of future trial‐based cost‐effectiveness studies. Methods In accordance with the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses Statement, this review examined all original, peer‐reviewed research in major databases and general searches published until June 2017, including randomised clinical trials, pilot studies, or feasibility studies about interventions for older adults with dementia or cognitive impairment. Results Forty‐one studies were identified. Only 8 collected the resource use data using adapted Client Service Receipt Inventory (CSRI), Resource Use Inventory (RUI), cost diary, or study‐specific questionnaire. Quality of life was assessed using a wide range of instruments. The most frequently used dementia‐specific instrument was Quality of Life in Alzheimer's Disease (QOL‐AD) and Dementia Quality of Life questionnaire (DEMQOL). Among the generic measures, EuroQol 5‐dimentison (EQ‐5D) was mostly used to collect health utility data, and Short Form surveys (SF‐36 or SF‐12) were widely to measure general health. Conclusions Several useful resource use and quality of life measurement instruments have been identified by this review. For resource use, CSRI was mostly used, but no studies have used Resource Utilisation in Dementia (RUD); for quality of life, we recommend the inclusion of dementia‐specific DEMQOL, generic SF‐12, and health utility EQ‐5D‐5L, based on both self‐report and proxy‐report.