A comprehensive look is taken at the rural-urban variation in extended familism among a segment of the population for which extended familism purportedly is especially salient: lower and working class black Americans. The study is guided by the general hypothesis that rurality/urbanism affects extended familism when nonecological variables are held constant. Differences by two dimensions of rurality/urbanism are analyzed--current place of residence and rural-urban experience. Three general dimensions of extended familism are examined: patterns of coresidence, amount of interaction among kin not living in the same households, and relative functionality of interaction with kin to nonkin. Because extant evidence and theoretical bases for predictions of relationships between rurality/urbanism and extended familism appear contradictory, no attempt is made to hypothesize and test the direction of rural-urban differences. The hypothesis that no rural-urban differences exist is supported with some caution since the statistic used for significance is sensitive to sample size, and because the sampling procedures for this study are not random. Another finding is that both the non-ecological and ecological variable effects are insufficient to explain as much as one-half or more of the variation in extended familism among the blacks. This indicates that all of the important ecological and/or nonecological factors affecting extended familism are not tapped by this study. (Author/AM)