The Chack Gajaria City wetland in Lucknow district, Uttar Pradesh, was conducted the diversity of alien invasive flowering plant species: their growth and life forms, habitat preferences and modes of introduction. The study resulted in documenting 62 alien angiosperms representing 54 genera of 27 families. The species such as Pistia stratiotes and Pontederia crassipes as water plants and Ipomoea carnea subsp. fistulosa, Typha angustifolia as amphibious and Parthenium hysterophorus as land species were found highly invasive. The most dominant families with invasive alien species were Fabaceae (9 spp.), Asteraceae (7 spp.), Malvaceae and Amaranthaceae  (5 spp. each) and Solanaceae and Cyperaceae (4 spp. each), Convolvulaceae and Poaceae (3 spp. each) while the rest of families were either with two or one species each. These findings provide the baseline information and emphasized the need for regular monitoring, early detection, effective management and control of invasive alien species in this urban wetland.