Use of respite services by 275 aging families of adults with mental retardation was examined over a 4.5-year period. Although more than twice as many families used respite in 1993 compared to 1988, over half never used respite during this period. Most families using respite received in-home services, in moderate amounts, and with high levels of satisfaction. In an analysis of predictors of respite use, the only significant predictor in 1988 was poorer functional abilities of the adult with mental retardation. By 1993, respite use was predicted by three characteristics: poorer functional abilities, better health in the adult with mental retardation, and greater maternal caregiving burden. These findings reflect variability in aging families' needs for support and changing respite policies.