Background: In brick kiln and construction industry the exposure to carbon monoxide and silica dust is the most common occupational hazard to the workers in these industries. A study on occupational health hazards of working women in these two unorganized sectors was undertaken by Lokmanya Medical Research Centre. Objectives: To study the effect of work site environment on the health of the women working in brick kiln and construction industry. An attempt was also made to study the seasonal changes in the concentration of carbon monoxide and dust at the worksite. Material and Methods: A cross-sectional study was conducted among the working women (age 18-40 years) at brick kilns and construction sites during summer and winter season. They were examined primarily to assess the effect of working environment on health. Gasteck Detector Pump of model 800 and air sampling instrument (SKC Air Check–52) were used to measure concentration of carbon monoxide and dust in the air respectively. Results: There were 66% of women who were in the age group of 18-40 years and most of them (94%) were married. At brick kiln sites, average CO exposure was 62.8 ppm and 55.5 ppm and average dust exposure was 3 3 146.1 mg/m and 91.4 mg/m in summer and winter season respectively.At construction sites, average dust exposure was 41.5 ppm and 90.8 ppm in summer and winter. Conclusion: Both exposure to CO and dust were more in summer than in winter in brick kiln industry whereas in construction industry the exposure to dust was more in winter season. A high level of morbidity in the form of headache, bodyache, problems with vision, cough and breathlessness were observed in both industries. It is strongly recommended to take pollution control measures.