A vast literature asserts that competition among jurisdictions can mitigate corruption. However, empirical studies do not fully support such a conventional view. This paper points out a drawback of the conventional view, that is, it ignores the role played by the owners of immobile factors. Within a standard tax competition model, we amend the conventional view by incorporating the lobbying of the immobile factor owners, and show that fiscal decentralization can aggravate corruption. We also demonstrate that social welfare can be higher under decentralization than under centralization in some cases, whereas the immobile factor owners' lobbying will prevent such a superiority of decentralization from being the outcome. Moreover, we provide an example to show that a better policy outcome and a higher level of corruption can co‐exist, which contrasts with the general belief.