Several epidemiological studies have indicated that building dampness affects the respiratory health of the inhabitants. In this study we investigated the relationship between building dampness and respiratory symptoms in young Swedish adults. In 1993, as a part of the European Community Respiratory Health Survey stage II, subjects were invited to participate in a detailed interview-led questionnaire, spirometry, methacholine challenge and measurement of total and specific IgE. A total of 1853 of the 2084 selected subjects participated in this study (88.9%). One hundred and thirty-six (7.4%) subjects reported water damage in their homes in the last year and 318 (17.3%) subjects reported visible molds during the same period. Seventy-four (4%) subjects reported both water damage and visible molds in the last year. This subgroup, with 74 subjects had significantly more attacks of breathlessness both when resting (OR 3.2 (95% CI 1.4-7.2)) and after effort (OR 2.7 (95% CI 1.3-5.6)) compared to subjects reporting no water damage or molds. Long-term cough was also more common in this group (OR 2.2 (95% CI 1.2-4.0)). This study adds evidence to a relationship between damp buildings and respiratory symptoms.