Disparities in cancer outcomes for people from culturally and linguistically diverse (CALD) groups are well known. Improving CALD patients' active participation in treatment processes holds potential to improve outcomes, but little is known of effective strategies to facilitate this. This systematic review investigated interventions to improve three aspects of participation in cancer care among CALD groups, namely involvement in decision-making, communication with health providers and treatment adherence. A comprehensive search of electronic bibliographic databases was conducted to identify intervention studies that reported outcomes relevant to patient participation for CALD groups. Two reviewers independently critically appraised the studies and abstracted data. Of 10 278 potential articles, seven met the inclusion criteria, including three randomized controlled, three non-randomized and one mixed-method experimental studies. Interventions included the use of patient navigators, videos and decision aids. The impact on patient participation was varied. The effect of a decision aid and patient navigator interventions on communication with health providers was positive. While the use of a decisions aid successfully facilitated shared decision-making and patients' perception of treatment adherence, the use of patient navigators was ineffective. A computer support system was found to improve general patient participation; however little clarification of what this involved was provided. This systematic review identified few rigorous evaluations of interventions to improve treatment participation for CALD people with cancer, highlighting the lack of a robust evidence base to improve this crucial aspect of care. The development and evaluation of interventions for diverse populations remains a priority.