There is a risk that climate change will cause an increase of mosquito populations in Europe. Due to their nuisance to humans, there are demands to combat mosquitoes, mainly through spraying. These interventions, however, are expensive and associated with uncertainties concerning effects on biodiversity. This poses a dilemma for policy-makers, which makes it important to gain knowledge on what people’s discomfort comprises. Qualitative studies show that even where the mosquito prevalence is very high, risk perception can vary within the exposed community, indicating that prevalence is not the only thing that matters. There is, however, a lack of quantitative studies that investigate what these factors are. The aim of this study is to develop a scale for mosquito risk perception and to explore what factors are associated with this risk perception. Theories about place identity, social norms, environmental concern and values were used to identify relevant factors. A questionnaire was distributed to 317 persons in a Swedish community where mosquitoes have increased radically. The items concerning risk perception fell out as a unidimensional scale in a PCA and the internal consistency of the scale was good. First, Pearson correlation analyses were performed. Mosquito risk perception was positively related to place identity, descriptive social norms, and self-oriented environmental concern and negatively related to ecocentric values. Thereafter, the relative importance of the independent factors in explaining mosquito risk perception was investigated in a multiple regression analysis with gender, education and age as control variables. The most important predictor was descriptive social norms, but the other factors and gender - women had a higher level of risk perception than men - also contributed uniquely in explaining risk perception. Results are discussed in relation to the theory of social amplification of risk.