We extend the research on contamination effects in mixed-member electoral systems by considering the impact of “dual candidacies” in systems that combine SMD and open-list PR rules. We make three claims. First, we argue that dual-listed candidates have incentives to run campaigns that enable them to maximize their share of personal votes in both tiers. Second, the effect of a dual listing is conditioned by incumbency and party-list position. Finally, we argue that parties themselves benefit from strong dual candidates in the PR list election itself. To test our argument, we analyze the 2016 Lithuanian parliamentary election. Using elite interviews and statistical models of electoral data, our analysis supports our claims. We provide important contribution to contamination literature by demonstrating that parties received a direct, list-tier benefit from nominating SMD candidates, who successfully build personal vote coalitions.