We aimed to review all randomised controlled trial (RCT) data to explore optimal identification and treatment strategies of frail patients with Acute Coronary Syndromes (ACS). The protocol was preregistered (PROSPERO - CRD42021250235). We performed a systematic review including RCT's that 1; used at least one frailty assessment tool to assess frailty and its impact on outcomes in patients diagnosed with ACS and 2; used at least one intervention where change in frailty was measured in patients diagnosed with ACS. The Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE were searched on the 1st April 2021 and updated on 4th July 2023. Owing to low search output results are presented as a narrative synthesis of available evidence. A single RCT used a frailty assessment tool. A single RCT specifically targeted frailty with their intervention. This precluded further quantitative analysis. There was indication of selection bias against frail participants, and a signal of value for physical activity measurement in frail ACS patients. There was a high level of uncertainty and low level of robustness of this evidence. Data from RCT's alone is inadequate in answering the reviews question. Future RCT's need to address ways to incorporate frail participants, whilst mitigating selection biases. Physical performance aspects of the frailty syndrome appear to be high yield modifiable targets that improve outcomes. Intervention trials should consider using change in frailty status as an outcome measure. Any trials that include frail participants should present data specifically attributable to this group. •There is a lack of randomised evidence in frailty and acute coronary syndromes.•Only two trials met review inclusion criteria in this setting.•This reflects a limited evidence base in this growing population of patients.•Future randomised trials must prioritise adapting to including frail patients.