Objectives Prolonged armed conflict may constrain efforts to address non-communicable disease in some settings. We assessed the impact of armed conflict on cardiovascular disease (CVD) risk among civilians in low/middle-income countries (LMICs). Methods In February 2019, we performed a systematic review searching Medline, Embase, PsychINFO, Global Health and Web of Science without language or date restrictions. We included adult, civilian populations in LMICs. Outcomes included CVDs and diabetes, and eight clinical and behavioural factors (blood pressure, blood glucose, lipids, tobacco, alcohol, body mass index, nutrition, physical activity). We systematically reanalysed data from original papers and presented them descriptively. Results Sixty-five studies analysed 23 conflicts, and 66% were of low quality. We found some evidence that armed conflict is associated with an increased coronary heart disease, cerebrovascular and endocrine diseases, in addition to increased blood pressure, lipids, alcohol and tobacco use. These associations were more consistent for mortality from chronic ischaemic heart disease or unspecified heart disease, systolic blood pressure and tobacco use. Associations between armed conflict and other outcomes showed no change, or had mixed or uncertain evidence. We found no clear patterning by conflict type, length of follow-up and study quality, nor strong evidence for publication bias. Conclusions Armed conflict may exacerbate CVDs and their risk factors, but the current literature is somewhat inconsistent. Postconflict reconstruction efforts should deliver low-resource preventative interventions through primary care to prevent excess CVD-related morbidity and mortality. PROSPERO registration number CRD42017065722