Breast　cancer　(BC)　is　one　of　the　most　prevalent　malignancies　and　the　major　contributor　to　cancer　mortality　in　women　globally,　with　a　high　degree　of　heterogeneity　and　a　dismal　prognosis.　As　drug　resistance　is　responsible　for　most　BC　fatalities　and　advanced　BC　is　currently　considered　incurable,　finding　innovative　anti-BC　chemotherapeutics　is　urgently　required.　Indole　and　its　analog　isatin　(indole-1H-2,3-dione)　are　prominent　pharmacophores　in　the　development　of　novel　medications,　and　their　derivatives　exhibit　strong　anticancer　activities,　also　against　BC.　In　particular,　indole/isatin　hybrids　exhibit　significant　potency　against　BC　including　multidrug-resistant　forms　and　excellent　selectivity　by　influencing　a　variety　of　biological　targets　associated　with　the　disease,　supplying　helpful　building　blocks　for　the　identification　of　potential　new　BC　treatment　options.　This　review　includes　articles　from　2020　to　the　present　and　provides　insights　into　the　in　vitro　and　in　vivo　anti-BC potential,　molecular　mechanisms,　and　structure–activity　relationships　(SARs)　of　indole/isatin　hybrids　that　may　be　helpful　in　the　development　of　innovative　anti-BC　chemotherapeutics.　©　2023　Deutsche　Pharmazeutische　Gesellschaft.