Based on a fragment of mitochondrial DNA and two nuclear protein-coding loci Gvoždik et al. (2010) suggested that Anguis fragilis is a species complex comprised of at least four species in Europe. Gvoždík et al. (2013) subsequently split A. fragilis into five species on genetic grounds. This arrangement has been accepted (Speybroeck et al. 2016), although morphological differences remain to be fully characterised (Uetz et al. 2019).

Global and European regional assessment: Least Concern (LC)
EU 27 regional assessment: Least Concern (LC)

This species is endemic to Europe, where it is widespread across the region. It is assessed as Least Concern both globally and for the EU27 Member States in view of its wide distribution, presumed large and stable population, occurrence in a number of protected areas. Although there are localised declines, the species is unlikely to be declining fast enough to qualify for listing in a threatened category.

This species is endemic to Europe (Gvoždík et al. 2021), where it is present throughout most of western and central Europe, although it is replaced throughout Italy and immediately adjacent areas by Anguis veronensis, the Italian Slow Worm, and is absent from northern Scandinavia, central and southern Iberia, and most Mediterranean Islands. Range limits relative to other slow worm species remain unclear (Speybroeck et al. 2016) and contact zones with other species within the genus require further investigation (Jablonski et al. 2021). As presently understood, this species reaches its eastern range limit in central Poland, Kaliningrad (Russia; Ananjeva et al. 2006), eastern Czechia, and the western Balkans, and reaches northern Greece in the south (Jablonski et al. 2021). Subpopulations further east are now referred to A. colchica, the Eastern Slow Worm (Gvoždík et al. 2021). Recent genetic evidence that A. fragilis extends along the Baltic coast indicates that the contact zone between these two species extends from the Balkans to northern Poland (Gvoždík et al. 2021). It can be found from sea level up to 2,700 m asl (Jablonski et al. 2021).

Ireland is not considered part of its native range and is not mapped for this island by Speybroeck et al. (2016). Although it has been reported from Ireland since 1972, and it is known to be established there, it has generally been assumed "...without any evidence or credibility..." that this subpopulation represents an introduction from Britain in the early 1970s (Parry 2020). Jablonski et al. (2021) suggest that the species may be a genuine relict in Ireland, and consider its origin on the island uncertain in the absence of evidence for human-mediated dispersal.

It can be relatively common, but localised declines are believed to be taking place through the conversion of land to intensive agriculture. Changes in population abundance is difficult to determine as the species spends a considerable time underground (B. Schmidt pers. comm.).

Subpopulations of this species can be found in grassy meadows, woodland glades, heathland, at the forest edge, in forest clearings, with alluvial forest, under hedgerows, in parkland and rural gardens. Animals have been found burrowing in loose sand and under rocks. It is a viviparous species; the female gives birth to between three and 26 young.

It is threatened in parts of its range by a general loss of habitat due to agricultural intensification and urbanization, fires and re-afforestation of clearings. Animals are also killed on roads in parts of its range, and predation by domestic cats is a threat in some areas. Unmediated mitigation projects, such as the translocation of subpopulations, are a threat to some UK subpopulations. It is not collected commercially.

There is no significant use of or trade in this species, although individuals under this species name do occur for sale in the specialist collector market.

This species is listed on Appendix III of the Bern Convention and occurs in many protected areas throughout its range. It is protected by national legislation in some countries of its range (e.g., in Austria, Germany, Sweden and Switzerland). It is categorised as Least Concern in Switzerland (Ursenbacher and Meyer 2023), France (UICN France, MNHN and SHF 2015), Norway (Dervo et al. 2021), Sweden (Thurfjell et al. 2020), Greece () and Denmark (Moeslund et al. 2019).

Further studies may be needed into the distribution of this species, including further taxonomic research. Monitoring of population size and trends is suggested, as well as research into the impact of threats.