An examination of demographics is crucial for understanding sustainable tourist behaviour and its boundaries. This study measures the impact of demographics on tourists’ environmental perceptions and vacation behaviours. This study utilizes a quantitative approach, and uses data gathered from 440 international tourists visiting Turkey. In accordance with the research model, t-test and one-way analysis of variance were performed. Key findings signify a considerable difference in the perception scores regarding environment-related issues based on the participants’ gender, age, monthly income and marital status. Furthermore, tourists’ green product purchasing behaviour scores show a statistically significant difference based on their age. However, a statistically significant difference was not determined in the environmentally sustainable vacation behaviour scores based upon the demographics of the tourists.