This snake is typically found in damp places, such as wet meadows, around standing water and along the banks of streams. It is sometimes found a long way from any standing water and can often be found in wooded localities and in heathland. It is tolerant of heavily-modified lansdcapes where suitable water sources are present, and can live in domestic gardens and urban parkland. In Cyprus, sparsely-distributed springs within ephemeral stream systems appear to be important for the Troodos Mountains subpopulation, while lowland records are associated with small natural wetlands or artificial irrigation pools (Zotos et al. 2022).

This species swims well and typically forages on fish and amphibians. It also eats young birds and small mammals. Larger females may lay up to 100 eggs (but usually fewer) during June and July (Speybroeck et al. 2016). Young females of Natrix helvetica lay about 10 eggs, which is presumably also the case for this species (Spellerberg 2002).

This species ranges widely through the European region, with a western range limit in Germany and Switzerland where it occurs sympatrically with Natrix helvetica, and has an eastern European range limit in European Russia (Kindler et al. 2017). It is absent from northern Scandinavia and Crete (Greece). It occurs on Cyprus, where species distribution models conducted in 2022 revealed a geographic range larger and wider that was previously thought in both the Troodos Mountains and Paralimni (Zotos et al. 2022). It is known from isolated, individual records in the Crimean Peninsula (Ukraine).

From Europe, it ranges through Asian parts of Russia eastwards into Kazakhstan (where it occurs through the northern half of the country south approximately to the northern boundary with the Caspian Sea. 19th Century records from the east coast of the Caspian have never subsequently been confirmed - T. Dujsebayeva pers. comm. 2017), Turkmenistan (the valley of the Atrek River, and the channel linking Maloe Delili with the Caspian Sea; Ananjeva et al. 2006), China and northern Mongolia. It occurs in most of Türkiye, the Caucasus, and in northwestern Syria (only known from a couple of localities where it is very rare). In Iran, it has been recorded from Mazandaran Province, Ghilan Province, East Azerbaijan Province and Central province (Latifi 1991). Globally, it ranges from sea level up to 3,060 m asl.

This species is listed on Annex III of the Bern Convention. It is protected by national legislation in some range countries. It is present in many protected areas throughout its range. The construction of corridors underneath roads could aid in significantly reducing mortality on roads for some populations (J.M. Pleguezuelos pers. comm. 2008). N. n. natrix is categorised as Endangered in Switzerland in the last Red List (Monney and Meyer 2005, OFEV and info fauna 2023). N. natrix cypriaca is considered Critically Endangered (Blosat 2005) but has been subject to very few effective conservation measures, with most management targeted at the near-extirpated Xyliatos dam subpopulation (Baier et al. 2013). A captive breeding program for this subspecies failed due to a lack of specimens (Baier et al. 2013). The remnant subpopulations are now protected in Natura 2000 sites and a species recovery plan is in place, but more effective protection and management of these areas is required (the latter including the complete removal of invasive fish and crayfish from these sites) (Baier et al. 2013). These authors recommend a complete distribution survey, annual monitoring and the establishment of a long-term captive breeding program; as of Zotos et al. (2021) none of these measures had been implemented. These latter authors propose installing small waterbodies with gabions that can manage water flow without damaging surrounding terrestrial habitat, as well as the expansion of Natura 2000 sites to encompass the new localities reported for the subspecies.

The success of the citizen science efforts reported by Zotos et al. (2022) highlight the importance of conducting further research to clarify the species' distribution and population system, and these authors recommend developing a systematic monitoring programme. These new findings have permitted the creation of species distribution models examining the species' potential future distribution in the Troodos Mountains under two climate change scenarios, resulting in a predicted reduction of species' distribution in the Eastern Troodos Mountains by up to 50% (Stamatiou 2022). Least Cost Path Analysis (LCPA) was conducted to identify connectivity corridors in need of management and conservation for the species (Stamatiou 2022).