A questionnaire survey was conducted to examine the socio-behavioral interaction between smokers and nonsmokers in a workplace situation. A socio-behavioral interaction is hypothesized to be centered around the subjective discomfort such as 'bothered feelings' towards involuntary smoking among nonsmokers. Study subjects were 1,134 nonsmokers and 1,457 smokers working in 21 small-scale production companies in Japan. Among nonsmokers, a combined 93.3% reported 'perceived exposure to smoking', 'always', 'often', or 'sometimes' compared to 6.6% reporting 'never'. Similarly, 74.6% experienced 'bothered feelings' 'sometimes', 'always', or 'often' compared to 25.3% reporting 'never'. A combined total of 39.4% expressed their discomfort to smokers 'sometimes', 'often', and 'always' compared to 60.6% who 'never' did. In contrast, 59.1% of smokers responded that they smoked with consideration of nonsmokers' presence (interpersonal awareness) 'sometimes', 'often', and 'always' compared to 41.0% for 'never'. 'Bothered feelings' among nonsmokers was significantly lower among those with past smoking history and correlated positively with 'perceived exposure to smoking' (rs = 0.22, p less than 0.001) and with 'expression of discomfort among both male (rs = 0.32, p less than 0.001) and female nonsmokers (rs = 0.34, p less than 0.001). Among male smokers 'interpersonal awareness' was significantly higher for those with less cigarette consumption and with past history of smoking cessation. A regression analysis was performed using mean scores calculated for smokers and nonsmokers of each workplace. Lower 'bothered feelings' of nonsmokers significantly correlated with higher 'interpersonal awareness' of smokers (r = -0.59, p less than 0.005). These finding imply the presence of socio-behavioral interactions between smokers and nonsmokers and thus suggest the significance of workplace education on involuntary smoking.