The article provides data on the flora of the former Southern Solid Waste Landfill in St. Petersburg. A rather unique partial flora and specific anthropogenic vegetation has formed at the landfill, in which weed and exotic species of higher plants significantly quantitatively predominate over native species (approximately 68 % to 32 %). As for the mass character of the plants themselves, in a number of cases the amount of adventive species reached 99 %. A large number of rare alien species were identified as part of the flora of the landfill, including such as Punica granatum, Vitis vinifera, Melo vulgaris, Citrullus vulgaris, Phytolacca americana, Glycine max, Physalis species, etc. that do not fall of cultivation in the North-Easter Russia because of their thermophyte nature. The article contains a list of plant taxa identified at the city landfill site during a survey of adventive flora in July-August 1999, including 179 species from 36 families of flowering plants, of which 122 species are alien. The main aboriginal species we encountered are also given. Despite the fact that the survey was conducted almost 20 years ago, over the past years, no new data on the composition of the flora and its dynamics has been published on large landfills and solid waste landfills in St. Petersburg, in connection with which we publish these materials. The data obtained by us can serve as the basis for studying dynamics of flora in such unique habitats.