This paper reports a study of paddy vegetation in central Laos. Plants were inventoried and vegetation types classified. Relationships between vegetation and agricultural practices were identified. A total of 184 wild herbaceous species and 17 cultivated species were recorded in two villages. Of the wild species, 19 were used by local people, four were rare species, and three were major weeds. Paddy vegetation was arranged in order of water regime from shorter to longer hydroperiod by DCA. The factors contributing to high species diversity were: (1) the presence of species unique to different paddy types; (2) the presence of remnant species from original vegetation; and (3) the impact of agricultural practices. Thus, at this study site, multiple plant species coexisted in paddy fields under various agricultural practices, and some species were essential sources of food or were used in other ways to support the subsistence livelihoods of local residents.