This study explored the views of Minnesota renters and apartment owners or managers about environmental tobacco smoke (ETS) transfer between units in multifamily buildings and about smoke-free housing. A convenience sample of 49 decision makers who manage 27,116 rental units in Minnesota were aware of some ETS transfer in their buildings, but most felt it was rarely or never a significant factor in tenants' decisions to rent or to move. Most of those who had never designated a building smoke free had little or no interest in doing so, due to concerns that it would increase vacancy rates, constitute discrimination, or engender costs for enforcement. Owners who had already designated smoke-free buildings, however, had seen mostly neutral or positive effects on vacancies, turnover, and time required to manage the buildings, and planned to continue offering them. A total of 48% of households in a random sample of 405 reported that at times ETS enters their apartment from elsewhere; 10% said this occurs often or most of the time. Of those experiencing ETS transfer, 37% said it bothered them a lot or so much that they were thinking of moving. Only a small fraction of renters currently live in smoke-free buildings, but nearly half would be extremely or very interested in doing so. Interest is high across ethnicities, income levels, rent levels, and age groups and regardless of whether the household has children. 54% of respondents would be very likely to choose a smoke-free building, all other things being equal, and 34% would be willing to pay more to live in one.