The purpose of this work was to assess the relation between exposure to secondhand smoke (SHS) at work and reported respiratory and sensory symptoms. A cross-sectional telephone survey of 382 nonsmoking indoor workers in Victoria, Australia was used. After controlling for potential confounders, exposure to SHS at work for part of the day was significantly associated with an increased risk of wheeze (OR = 4.26), frequent cough (OR = 2.26), sore eyes (OR = 3.77), and sore throat (OR = 2.70). Among workers who had not experienced a cold in the past 4 weeks, we found strong dose–response relationships between increasing levels of exposure to SHS at work and morning cough, frequent cough, sore eyes and sore throat, and a positive relationship for wheeze. These findings provide compelling evidence that nonsmoking indoor workers are adversely affected by exposure to SHS at work and underline the importance of workplace smoke-free policies in protecting the health of workers.