Astragalus gines-lopezii is a perennial herb, endemic to the south of the Iberian Peninsula. It has been classified as ‘Endangered’ by the Extremadura Regional Catalogue and placed in the equivalent category (EN D) of the National Red List because only one population in the world is known. Conservation of A. gines-lopezii requires a greater understanding of its population size, seed ecology and germination conditions. The latter issues are particularly important when establishing a reintroduction programme. This species was observed in nine colonies on the same mountainside, the largest of which consists of 60 plants. In this study, we compare the ability of the seeds to germinate under various conditions. Unlike most other members of the Fabaceae, the seeds of A. gines-lopezii do not need physical or chemical pre-treatment in order to germinate; instead they require a photoperiod for optimal germination. This study will facilitate a more in-depth understanding of this rare and poorly known species.