BACKGROUND: Second Hand Smoke (SHS) has been widely demonstrated as a risk factor for many health problems. Air Quality Monitoring Survey in 2011 at 78 public places in the city of Semarang with Side pack Aerosol tool obtained the data that the average of PM2.5 in places where smoking allowed was 94.76mg/m3 and in the place where smoking was not allowed smoking was 34.6Omg/m3. Café and restaurant was the public places with the highest PM2.5 levels. The average of PM2.5 in restaurant was 72.6OmgIm3, while in the café was 164.84 OBJEC1’IVE: This research aims to determine how the effects of secondhand smoke exposure on lung function and urine cotinine levels of café and restaurant employee in the Semarang city. METHODS: Data is collected from 13cafes and restaurants and the respondents are 70 non-smokers employees. The instruments used are spirometry to determine lung function, enzymelinked iniinunosorbent assay (Elisa) to measure urine cotinine, side pack aerosols to measure PM2.5, and questionnaire to identity the characteristics and SHS exposure. RESULTS: Most of the employees, 52 people (74.3%) have normal pulmonary function. However, there are 14 people (20%) have mild restriction, 2 people (2.9%) have mild obstruction and 2 people (2.9%) have moderate obstruction. Moderate obstructive lung function problems l00%occurred in cafe employee. The average level of urine cotinine of cafe employee is 42.9O2ngIml, while a restaurant employee is 33.609 ng/ml. The average of PM2.5 levels in the Cafe was 121.65 tg/ m3, twice as much compared to the average of PM2.5 levels in Restaurant (68.27 .tgIm3). There is a positive correlation between time of SHS exposure per day and urine cotinine levels (rho = 0.364, p-value = 0.002) and there is a relationship between colleague behavior and urine cotinine levels (p-value = 0.006). The age is correlated with lung function (rho = -0.272, p-value= 0.023) and there was inversely correlation between urine cotinine and lung function (rho = -0.266, p-value 0.026). RECOMENDATION: Semarang City Legislative should establish The Smoking Free Area Law immediately and followed by firm law enforcement for the protection of the people from secondhand smoke exposure and prevent theni from many further health issues.