The use of exotic cordgrasses in salt marsh restoration projects has caused important negative environmental impacts and little is known about the possibilities of applying the endangered cordgrass Spartina maritima as a biotool at many European estuaries where it is the only native cordgrass. This paper discusses the planning and the development of an innovative restoration project based on S. maritima plantations in Odiel marshes (S.W. Iberian Peninsula). Our ecological restoration project had four specific goals: (1) to recover native vegetation, restoring the degraded landscape; (2) to phytostabilize oil-polluted sediments; (3) to prevent erosion and stabilize banks; and (4) to promote the conservation of S. maritima. Spartina maritima was planted at two physiographical locations: slightly sloping channel banks and flat interior marshes. Nonsuccessional stands of S. maritima develop at the channel banks where the marsh surface was stabilized. In contrast, successional stands of S. maritima grown in flat interior marshes are being replaced naturally by Sarcocornia perennis.