<p>Periodic vernal ponds of floodplain forest represent an ideal breeding ground for <i>Aedes</i> mosquito. Moist soil along the pond margins preserves diapausing eggs by preventing desiccation and allowing dormancy until inundation induces hatching. Surprisingly, the current knowledge of distribution and density of eggs (egg bank) is still limited. This information is crucial for prediction of possible mosquito calamities. In this study, we examined the lateral and vertical distribution of eggs along transects in four selected ponds, assessed their densities, and attempted to estimate the area available for oviposition. Sediment samples were collected with a pedological probe during autumns 2022 and 2023. Significantly more eggs were observed in the uppermost sediment layer. In general, most of the eggs were located at the pond margins. The total density of eggs varied between years and localities. The area suitable for oviposition varied considerably between ponds. Egg distribution within ponds was patchy with the highest densities concentrated in marginal zones shaped by hydrological conditions in previous year. Therefore, the egg bank in the studied area may be relatively variable. Measuring the height of oviposition sites relative to the falling water level would be useful, as it could improve predictions of hatching dependence on future inundation height.</p>