Managers trying to preserve populations of endangered carnivores are often forced to choose between restoring habitat to allow larger breeding populations or reduce risks of mortality to increase survival rates. We modelled the viability of a metapopulation of the Iberian lynx (Lynx pardinus) under several scenarios (habitat restoration, anti-poaching, reduction in road kills) in a real landscape to evaluate their relative effects. Increasing carrying capacity was highly effective when performed on the local populations that acted as sources but had no effect when carried out in the sinks. Realistic scenarios consisting of partial removal of the human-related mortality (assuming additive effects of causes) predicted high risk of extinction. When combined, the effects of both management options are highly dependent on where they are carried out. If the sinks are the only targets of carrying capacity enlargement, a complete removal of human-caused mortality is required, whereas increases in the carrying capacity of sources are always effective. The metapopulation risk of extinction decreases dramatically (from 45.5% to 2.1% in 100) if connectivity among source populations can be improved. According to our work, only a detailed knowledge of the spatial and demographic structure of the populations, combined with simulations of realistic situations, can help managers to select the a priori optimal strategy, which probably combines different management options.