Introduction: Ethnicity, female gender, and older age are associated with lower rates of receipt of bystander cardiopulmonary resuscitation (B-CPR). Increasing telephone-assisted CPR (T-CPR), or provision of CPR instructions when individuals call 9-1-1, may improve B-CPR rates. It is unknown whether provision of T-CPR may overcome ethnic, gender and age variation seen in B-CPR. Objectives: We sought to assess whether provision of T-CPR may overcome ethnic, gender, and age variation seen in B-CPR. We hypothesized that the provision of T-CPR will improve B-CPR and reduce differences associated with ethnicity. Methods: We conducted a retrospective study of adult, non-traumatic out-of-hospital cardiac arrests (OHCA) from the Singapore registry (4/2010-12/2016). We assessed variation in B-CPR by ethnicity, female gender, and increased older age, stratified by receipt of T-CPR. We examined the differences using descriptive statistics and multivariable logistic regression accounting for confounding. Results: From 2010-2016, the Singapore registry contained 12,546 OHCA events. Excluding traumatic, EMS witnessed, and healthcare facility arrests, 7,997 events were analyzed. Of these, mean age was 66±19 and 65% were male. B-CPR was administered in 53% of the events, while T-CPR was provided in 30% of the events. In a univariate analysis, female gender was associated with variation in B-CPR if T-CPR was not provided (F: 29% vs M: 35%, p<0.01) and provision of T-CPR reduced this variation (p=0.17), but this association was not observed in the multivariable logistic regression. When adjusting for confounding, ethnicity was associated with variation in B-CPR if T-CPR was not provided (p<0.01), while provision of T-CPR reduced this variation (p=0.50). Additionally, increased older age was associated with a decreased likelihood of receipt of B-CPR if T-CPR was not provided (OR: 0.99 (0.98-0.99), p<0.01), while this variation was not observed with provision of T-CPR (p=0.50). Conclusion: T-CPR modified the known B-CPR differences seen in ethnicity and increased older age, but did not modify differences seen in gender when controlling for other covariates. These findings may help inform public policy and methods to decrease variation and increase B-CPR.