This gecko was formerly considered a subspecies of the widespread Phelsuma madagascariensis. It was elevated to full species status by Raxworthy et al. (2007). This change has since been supported in a revision of Malagasy Phelsuma based on genetic data (Rocha et al. 2010).

Listed as Least Concern on the basis that, while it has a known extent of occurrence of 9,226 km², it may be more widespread in northern Madagascar than currently indicated, it is apparently common and tolerant of disturbance within its known range, it is known from at least two protected areas, and there are no known major threats.

This large day gecko is naturally restricted to Madagascar, where it has been confirmed from the northeast and from the Sambirano region of the island's northwest (Raxworthy et al. 2007; Rocha et al. 2009, 2010), as well as from the island of Nosy Be. The lizard may be more widespread in northern Madagascar, and further research is needed to establish its occurrence within this range and the exact limits of its distribution. A population has been introduced to Mauritius, where it is widespread (N. Cole pers. comm. July 2011), and it has also become established on Réunion (N. Cole pers. comm. July 2011). This species occurs from sea level, and has been recorded as high as 900 m asl. in Montagne d'Ambre. In its native range the species has an estimated extent of occurrence, based on the extent of known sites, of 9,235 km². As several records at the margins of the known distribution areas are very recent (Labanowski and Lowin 2011, Durkin et al. 2011), the gecko may be more widespread between known sites than is presently recognized.

This is a common species where it occurs, but is apparently local. It was by far the most abundant lizard encountered during a 20 day survey of Montagne des Français, constituting 91 of 172 lizard records, 78 of which were taken in orchards (D'Cruze and Kumar 2011). There is no information on population trends.

Although this species occurs in both intact and degraded native forests it is also found in other habitats, including orchards, where there is a good range of perches and an ample food supply (D'Cruze et al. 2009). It is common on large trees and on the walls of buildings in towns and villages.

This species is highly tolerant of habitat modification. It may be subject to locally high levels of collection for the pet trade (D'Cruze et al. 2009).

Phelsuma madagascariensis is subject to legal commercial export from Madagascar with an export limit of 2,000 individuals a year, and individuals of P. grandis are probably exported as P. madagasarcariensis grandis. This large and charismatic species is widely bred in captivity.

This species occurs in anthropogenic habitats as well as native forest, including protected forests in Montagne d'Ambre National Park and the new protected area at Montagne des Français. The taxon was recently elevated to a full species and it is now important to update its distribution, biological and ecological information. Updates to the CITES database and national legislation are needed in light of the taxonomic changes.