While a division of domestic space into separate sectors dedicated to different activities has been suggested for a number of Upper Paleolithic hunter-gatherer sites, it has never been demonstrated based on plant remains from this period. Moreover, due to the usual scarcity of plant macrofossils in archaeological deposits, only animal food preparation activities associated with hearths have been reported in the literature on Near Eastern prehistory. Ohalo II (Israel) is the first Upper Paleolithic site where such a patterned use of interior space and plant processing are evidenced by the distribution of plant remains on a sealed floor of a brush hut. This paper describes and interprets the distribution of almost 60,000 identified seeds and other plant remains on that floor, proposing a reconstruction of three activity areas in the interior of the 12-m² hut: processing of food centered on a grinding stone; a flint knapping area; and an access area in between. Finally, it is suggested that these activity areas might represent male-female division of labor.