There is little comparative research on what causes candidates in elections across the world to ‘go negative’ on their rivals – mainly because of the scarcity of large-scale datasets. In this article, we present new evidence covering over 80 recent national elections across the world (2016–2018), in which more than 400 candidates competed. For the first time in a large-scale comparative setting, we show that, ceteris paribus, negativity is more likely for challengers, extreme candidates, and right-wing candidates. Women are not more (or less) likely to go negative on their rivals than their male counterparts, but we find that higher numbers of female MPs in the country reduces negativity overall. Furthermore, women tend to go less negative in proportional systems and more negative in majoritarian systems. Finally, negativity is especially low for candidates on the left in countries with high female representation, and higher for candidates on the right in countries with proportional representation (PR).