Phenological phases, as adaptive strategies, have been studied in Mediterranean serpentine shrubland vegetation and their endemisms, in the South of the Iberian Peninsula. The aim of this research is to obtain the phenological characterization of the serpentine flora and to make a comparison between endemic serpentine and non‐serpentine plants in different years and altitudes. For this purpose, data were taken in the serpentine ecosystem of Sierra Bermeja (Andalusia, Spain) establishing two plots on two altitudinal bioclimatic belts and during two different years. A total of 28 persistent taxa were studied, focusing on serpentinophytes, their allied (magnesicolous) and non‐serpentinophytes, trying to detect the possible differences between serpentine endemic taxa and non‐endemic plants. Phenological calendars and phenological patterns (phenophasic indexes) were obtained. The species showed phenophasic patterns similar to those of other studied Mediterranean flora: a phenological pause which coincides with summer and most plants behaved as summer semi‐deciduous with seasonal dimorphism. There were no statistically significant differences in phenology and in phenological indexes due to the altitude, to the year of sampling and due to the serpentine affinity. The best represented active phenophasic period of the species was 9‐11 months of activity although showing the summer phenological pause. Species with low index of reproductive/vegetative activity of the species predominated, employing more time/resources for vegetative functions, and with synchronous phenophases, where flowering and growth coincide (phenophasic pattern type I). The phenophasic period of serpentinophytes and magnesicolous taxa pointed to a certain delay in the period of flowering with respect to the group of non‐serpentinophytes, a result which could have reproductive implications.