Indoor, outdoor, and personal nitrogen dioxide (NO2) exposures were studied in a population of housewives. Daily Indoor and outdoor NO2 concentrations were measured and compared with simultaneously personal exposures of 17 housewives for 7 consecutive days in 17 houses. In this study, indoor and outdoor NO2 samples at home were collected only while the housewives were at home samples. Time activity patterns and house characteristics were used to determine the effects of these factors on personal exposure. Since housewives spent their times in indoor houses with mean of 78.3%, their NO2 exposures were associated with indoor houses NO2 levels (r= 0.89) rather than outdoor NO2 level (r= 0.85). Contribution of indoor NO2 concentration on personal exposure was estimated by 70.77% by using of mass balance model. The close association between measured indoor NO2 concentrations and measured personal exposure and contribution of indoor NO2 concentration suggests that measuring indoor concentrations of NO2 in the home is sufficient to estimate personal exposure accurately. Keywords：Housewives, Personal exposure, Nitrogen dioxide, Contribution