The authority has variously been given as Merrem, 1820 or as Milbert, 1812; the latter is followed here and is generally accepted (F. Glaw pers. comm. January 2011). Three lineages are known from Mauritius (Austin et al. 2004), and if these are described as separate species the conservation status of P. cepediana will need to be reassessed.

Provisionally listed as Least Concern on the basis that, although it has an extent of occurrence of 1,875 km², there are no known major threats to this species and it is widespread on Mauritius despite high levels of deforestation and anthropogenic pressure. If this species is later recognized to be a complex the conservation status of individual lineages will need to be reassessed; additionally, if it is found that invasive day geckos represent a threat to this species, it will require immediate reassessment.

This species is endemic to Mauritius, where it has been recorded from localities throughout the island (Harmon et al. 2007) and is also found on the southwest islet of Ile aux Benitiers (N. Cole pers. comm. July 2011). There is a historical record of this species from Ivoloina on the eastern coast of Madagascar where specimens were apparently released. There is an anecdotal report of this species from Ambanja on the northwest coast of Madagascar. It appears to have been recently introduced to Rodrigues, where it has been recorded from Port Mathurin (N. Cole pers. comm. July 2011). Unless its continued presence on Madagascar can be confirmed, this species should be considered as being extinct on this island (F. Glaw pers. comm. January 2011). The species has an extent of occurrence of around 1,875 km².

There is no evidence that any population of this species survives in Madagascar. It is widespread on Mauritius, where three different lineages occur, and can be found at high densities in even highly degraded habitats dominated by coconut palms and the invasive traveller's palm (Ravenala madagascariensis) (N. Cole July 2011).

This gecko is widespread in anthropogenic habitats and in traveller's palm (Ravenala mdagascariensis) on Mauritius, and is reported as being common in lowland dry forest containing a mix of native and exotic tree species (Harmon et al. 2007). The species exhibits a preference for palms and palm-like trees (such as Ravenala) with smooth fronds and water-filled crevices, which it probably uses for shelter and egg-laying as well as for foraging (Harmon et al. 2007). The diet includes insects and nectar (Harmon et al. 2007). In communities where other day geckos are present, this species is almost exclusively confined to palms, in which it appears to be competitively superior to congeners, and typically uses moderately broad perches at medium heights on its host trees (Harmon et al. 2007). There is no information on the habitats and ecology of this species in Madagascar.

The Bluetail Day Gecko is the sole pollinator and seed disperser for the endemic Mauritian plant Roussea simplex in the southern part of this plant's range (Hansen and Müller 2009a); the related P. ornata is presumed to act as the plant's pollinator in areas where P. cepediana is absent (Hansen and Müller 2009a). Experimental evidence indicates that lizards are strongly deterred by the presence of invasive ants on these now-rare plants, to the extent that gecko visits to ant-infested fruits and flowers virtually cease (Hansen and Müller 2009b). The same study showed a corresponding decline in infested plants' success at setting seed.

Habitat modification is ongoing and widespread in mainland Mauritius, although this species exhibits a high degree of adaptability to degraded habitats, where it can persist in large numbers (N. Cole pers. comm. July 2011). It is not clear whether the three different lineages of this species differ in their sensitivity to threatening processes, and research is underway to investigate this (N. Cole pers. comm. July 2011). It is likely that the introduction of the larger Madagascan day gecko P. grandis has resulted in the displacement of native day geckos (N. Cole pers. comm. July 2011), but it is unknown whether this represents a specific threat to P. cepediana. Levels of exploitation for the European pet trade are unknown, as this species breeds readily in captivity, but it is thought some collection of wild animals takes place. Trade is not presently thought to represent a threat to this species (N. Cole pers. comm. July 2011).

There is some trade in Mauritian day geckos, including Phelsuma cepediana, within Europe. It is likely that some animals are collected from the wild to support this activity (N. Cole pers. comm. July 2011).

There are no conservation measures for this species in Madagascar. In Mauritius it appears to be common and widespread. More research is needed into the taxonomic status of this species, and studies are underway to investigate the effects of threatening processes, including invasive geckos, on this species. As an endemic on a small, densely populated island the population should be closely monitored in case future threats arise.