Wetland restorations benefit wildlife, but wetland vegetation may promote mosquitoes. We studied the effects of removing joint grass (Paspalum distichum L.) on the abundance and distribution of immature mosquitoes in seasonal freshwater wetlands in California. In 4 >4-ha plots and one 29.8-ha field, joint grass was removed via herbicide and disking. Four untreated plots and one 4.1-ha field were controls. Fields were sampled every 7–14 days in early autumn by taking 75 dips along levees, plus a 25-dip circular transect 6 m from field edges. Untreated plots had 7 times more larvae and 20 times more pupae than did vegetation-removal plots. Similar densities of mosquitoes were found along edges and within fields.