We studied dampness and mold in China in relation to rhinitis, ocular, throat and dermal symptoms, headache and fatigue. A questionnaire study was performed in six cities including 36 541 randomized parents of young children. Seven self-reported signs of dampness were evaluated. Multilevel logistic regression models were used to calculate odds ratios (ORs). Totally, 3.1% had weekly rhinitis, 2.8% eye, 4.1% throat and 4.8% skin symptoms, 3.0% headache and 13.9% fatigue. Overall, 6.3% of the homes had mold, 11.1% damp stains, 35.3% damp bed clothing, 12.8% water damage, 45.4% window pane condens...