To the Editor: In their paper Agabiti et al1 estimated that 15% of the current asthma cases among children and 11% of the current wheezing cases among adolescents are attributable to parental smoking in Italy. We conducted a similar case-control study in the city of Mortara (a small town of 15,000 inhabitants in northwestern Italy); we selected from the archive of a general pediatric clinic the cases that presented at least two respiratory wheezing episodes in the period 1992–97 (96 children, 54 males and 42 females, average age 7.3 years). For each case we matched, from the same archive of patients, a child of the same age and sex without respiratory disease as a control. We collected the following variables for each group: history of family atopy (presence or lack), domestic cigarette smoke (smoking or non-smoking parents), time of birth (high or low respiratory disease incidence season), prematurity (pregnancy <38 weeks), breast-feeding (yes or no), and two descriptive variables of pollution in the area of residence (vehicular flow and atmospheric purity indexes - API). 2 We used a conditional logistic regression model for the analysis. 3 The overall relative risk for wheezing among the children exposed to parental smoking was 2.3 (95% confidential interval = 1.0–5.3);Table 1 summarizes the effect estimated for other variables in our data. Table 1: Odds Ratios and 95% Confidence Limits (95% CL) of the Relation between Respiratory Wheezing and the Variables Analyzed in the StudyOur findings confirm the results of Agabiti et al, as well as the effect of a high vehicular flow, the latter effect having already been widely documented. 4–7 Unlike other studies, we did not find a positive relation between wheezing and low API levels (that indicate dirtier air), probably because of the examined disease. 8 We measured respiratory wheezing risk; although wheezing is not a serious disease, it is a frequent complaint in children. As it may be impossible to improve urban air quality in a short time, cigarette smoke is the primary atmospheric pollutant that can be realistically eliminated from the environment over the short run. Massimiliano Panella Lucio Palin Michela Trada Gianni Bona Emanuele Garibaldi Emanuela Garibaldi