The purpose of this study was to implement an evidence-based prevention programme to reduce occupational skin diseases in a wet work occupation by educational activities and elements from an occupational health-management system. The effects were studied by telephone interviews using a standardized questionnaire (NOSQ-2002) with trade-modified questions on work and exposure. The study population consisted of all employees at 5 cheese dairies. At baseline, October 2002, a total of 557 answered (83.8%). At follow up 1 year later, a total of 650 current and former employees answered (81.8%). At 4 of the 5 dairies, the eczema frequency at baseline was relatively low (11.8% and 5.9% at intervention dairies; 7.0%, 10.4% and 33.3% at comparison dairies). On all the studied dairies, about one-third of the workers reported having 2 or more skin symptoms at baseline. At follow up, skin symptoms were reduced significantly on all dairies. Effects restricted to the intervention dairies included significant increases in the use of gloves and moisturizers. The comparison dairy with high eczema frequency at baseline introduced skin-care products, changed hand soap and mowed employees with skin problems, away from adverse working areas during the intervention period, and the frequency of eczema was significantly reduced at follow up.