[4] The preferred natural habitats of T. stephensi are coastal forest and shrubland, at altitudes from sea level to 225 m (738 ft).

T. stephensi is viviparous and has a low reproductive rate, with females giving birth to 1-2 young every other year.

As of 2012 the Department of Conservation (DOC) classified the Stephen's Island gecko as Nationally Vulnerable under the New Zealand Threat Classification System.

[3] The IUCN lists T. stephensi as endangered, as it occupies limited areas at a small population density.

A re-evaluation of T. stephensi's conservation status is necessary, as the species is now believed to be restricted to the three islands in the Cook Strait.