BACKGROUND: Despite the low prevalence of daily smokers in Sweden, children are still being exposed to environmental tobacco smoke (ETS), primarily by their smoking parents. A prospective intervention study using methods from Quality Improvement was performed in Child Health Care (CHC). The aim was to provide nurses with new methods for motivating and supporting parents in their efforts to protect children from ETS exposure. METHOD: Collaborative learning was used to implement and test an intervention bundle. Twenty-two CHC nurses recruited 86 families with small children which had at least one smoking parent. Using a bundle of interventions, nurses met and had dialogues with the parents over a one-year period. A detailed questionnaire on cigarette consumption and smoking policies in the home was answered by the parents at the beginning and at the end of the intervention, when children also took urine tests to determine cotinine levels. RESULTS: Seventy-two families completed the study. Ten parents (11%) quit smoking. Thirty-two families (44%) decreased their cigarette consumption. Forty-five families (63%) were outdoor smokers at follow up. The proportion of children with urinary cotinine values of >6 ng/ml had decreased. CONCLUSION: The intensified tobacco prevention in CHC improved smoking parents' ability to protect their children from ETS exposure.