Municipalities in Sweden are every fourth year required to create a risk and vulnerability analysis, identifying, prioritising and analysing the risks specific to the municipality. By looking at such analyses from 20 municipalities, this study show there is an unexpectedly high divergence of which risks municipalities prioritise, a divergence not explained by geography or demography. Some municipalities also prioritise unlikely or odd risks, such as solar storms, over likely ones. These observations warrant questions about on what grounds risk prioritising is made. Creating a risk and vulnerability analysis involves decision making under uncertainty, which studies have shown is subjected to systematic cognitive biases. An organisational environment focused on measurable results and audits may also make decision makers prone to these biases. This study utilizes psychological and organisational theories to examine the puzzle of divergence and the occurrence of unlikely risks in municipal risk prioritising. Through analysing a few observations, conclusions include that there is support for risk averse thinking, disadvantageous organisational conditions and political compromises giving room for short-sightedness and irrationality. A limited selection of municipalities and the interpretation of a specific risk value given in the risk and vulnerability analyses as being synonymous with risk prioritisation may affect the validity and reliability of the study. An array of reasons influences risk prevention strategies and the reasons dealt with in this study are far from comprehensive. Further research could explore how an interplay of factors influence risk prevention.