Can electoral systems determine how particularistic spending is distributed in developing countries? The ways in which legislators seek benefits for their constituencies, have been the subject of longstanding debate in political science. While the discussion has broadly focused on the theoretical consequences of electoral systems on legislators’ behaviour, little evidence has accounted for these alleged effects, especially in developing country settings. This paper focuses on particularistic spending in Honduras, providing a natural experiment to test different relevant hypotheses found in the literature. Since the early 1980s Honduras used a closed-list ballot with single-member and plurinominal districts electoral system. In 2004 the country moved to an open ballot structure keeping the same range of district magnitude. On the basis of original data from the Honduran Social Investment Fund, a battery of statistical tests is conducted. It is expected that under a closed-list system social spending per capita will increase as district magnitude shrinks, and the opposite will happen when an open-list system is in use. The evidence suggests that the change from a closed-list to an open-list system causes an increase in spending per capita. However, the interaction of type of ballot with district magnitude does not produce the results predicted by influential theories.