Introduction:
It has been noted in South Korea since September 2016 that at least half of the households residing in an apartment building were in favor of designating common areas such as the hallway, stairway, elevator and underground parking-lot as non-smoking areas. The purpose of this study is to examine changes in smokers’ behavior following the implementation of this smoke-free apartment building legislation.

Material and Methods:
A cross-sectional mobile survey was conducted among a convenience sample of residents of four apartment buildings in three regions of South Korea. The survey was distributed via notices posted on each apartment’s bulletin board for about one month. The apartment buildings’ adult residents were able to access the questionnaire using the Quick Response (QR) code provided on the notice.

Results:
A total of 378 residents, 38 of whom were smokers, participated in the mobile survey. Following the implementation of the smoke-free apartment regulations, smoking was reduced in public areas (e.g. hallways, stairways, and underground parking-lots) while smoking activity in other areas increased. Furthermore, 39.5% (n=15) of current smokers had attempted to quit, and 23.7% (n=9) who smoked outside (n=6) and inside the buildings (n=3) had changed their habits.

Conclusions:
The designation of non-smoking areas in apartment buildings may have had a positive effect on smokers’ habits in the short-term. In the future, efforts to support smoking cessation will be necessary for the creation of smoke-free community spaces, i.e. smoke-free areas in apartment buildings.