Children less than 6 years old are the most vulnerable group to get harm from Environmental Tobacco Smoke (ETS) exposure, especially their respiratory system. To determine the prevalence of ETS exposure and its association with asthma like symptoms among children less than 6 years old. A cross sectional study was conducted in between January till April 2014 among parents with children less than 6 years old in Selangor, Malaysia. A total of 142 parents were selected by simple random sampling and data were collected using guided questionnaire on ETS exposure and asthma like symptoms (cough and wheeze) among their children. A total of 52.8% of children found to be exposed to ETS, and 43.7% were exposed from their father. ETS exposure significantly associated with cough without cold (adjusted OR=5.46, 95% CI 2.37, 12.61), dry cough at night (adjusted OR=3.74, 95%CI 1.41, 9.95) and cough upon physical activity (adjusted OR=3.08, 95% 1.07, 8.89) among these children. Children less than 6 years old are vulnerable to respiratory problem due to ETS exposure especially on cough symptoms. More strategies should be developing to reduce the exposure to ETS.