In the paper entitled “No increase in the prevalence of asthma, allergies, and atopic sensitisation among children in Germany: 1992–2001” by I K Zöllner et al which appeared in the July 2005 issue of Thorax (2005;60:545–8), the authors apologise for a mistake which occurred in the reference list. Reference number 18 should be number 21 and references 19–21 should be listed as 18–20.