Balkan Snow Vole is a subfamily Arvicoline rodent, vulnerable species according to the IUCN Red List criteria. It is a tertiary relict and Balkan endemic, specific to karst areas of Dinaric Alps. Habitat of Balkan Snow Vole is complex and differently structured, varying from open meadows and rocky plains, to fragmented ridges and deep fissures under forest vegetation. Habitat complexity can significantly affect habitat use, migration and new territory invasion, and could also affect the connectivity of small, fragmented populations of Balkan Snow Vole. Sixteen specimens of captive Balkan Snow Voles were studied through two types of setups, to research behaviour in a new environment of varying complexity, and in a seemingly occupied environment with different olfactory marks. All trials were recorded at the same, previously determined time of day, during one hour. Twenty-five behaviours were analyzed using a computer program designed for animal behaviour coding, and the results were statisticaly analyzed to study the effect of presented setup, sex and season. Balkan Snow Vole explores the more complex environment longer, enters the scent-marked environment earlier, but shows no great differences in behaviour depending on the type of presented scent. Behaviour varies more depending on season than sex. Results could be used to assess the mobility of Balkan Snow Vole in natural habitat, to estimate the endangerment of its isolated populations, and to create a monitoring and protection plan for the species.