We sampled veliger (larval stage) zebra mussels (Dreissena polymorpha) from 2016-2019. Zebra mussels are invasive in Lake Mendota and were first detected in November 2015. Samples were taken at three different sites on Lake Mendota from June to August in 2016, and from June to November in 2018-2019, using a 0.5 m diameter, 64 micrometer mesh size plankton net for an 8 m depth tow. This dataset complements adult zebra mussel, zoobenthos, and phytobenthos data collected during the same time period, for which data is also archived with EDI.