Magnesium alloys have come to the fore as attractive lightweight structural materials owing to their high specific strength, whilst some of them are considered for bioresorbable implant applications. A new Mg-4Li-1Ca (LX41) alloy, processed by two-step rolling followed by annealing, showed extraordinary properties outperforming the existing Mg alloys in terms of specific strength, strain hardening ability, ductility, and cytocompatibility. The record-breaking superiority in mechanical properties combined with cytocompatibility qualifies the alloy for applications in lightweight engineering structures and bone implants. © 2016 Elsevier B.V. All rights reserved.