The aim of this study was to obtain preliminary exhaled breath condensate (EBC) pH values for healthy adult Croatian subjects, and to evaluate criteria for defining respiratory health of population providing normal EBC pH values in epidemiologic studies. In 109 adults without a history of lower airway symptoms (AS), four groups were described by narrowing the definition of "health" down to 1) without lower AS; 2) without lower and upper AS; 3) without AS, with normal FEV1 and bronchial normoreactivity; 4) without AS, with normal FEV1, bronchial normoreactivity, normal total IgE, and with negative skin prick test. Median EBC pH values did not differ between the groups (7.72, 7.73, 7.73, 7.73), but as health criteria got stricter, we observed a slight, nonsignificant increase in minimal pH values (6.95, 7.10, 7.20, 7.37). Median EBC pH values with interquartile range in the total sample (7.72; 7.63 to 7.76) were within the range previously reported by other authors. They did not differ regarding sex, smoking habit and atopic status, and were not associated with age, FEV1 or total IgE. The non-significant trend in EBC pH observed with stricter criteria of respiratory health and atopic status indicates the need for further research on criteria for defining healthy population in a larger sample. Ciljevi preliminarnog istraživanja bili su izmjeriti pH-vrijednosti kondenzata izdaha (pH KI) odraslih stanovnika Hrvatske bez dišnih poremećaja te utvrditi kriterije potrebne za definiranje zdravlja dišnog sustava populacije u kojoj se planiraju utvrditi normalne pH-vrijednosti KI-a. U uzorku od 109 odraslih osoba bez tegoba od strane donjih dišnih putova, sužavajući definiciju "zdravlja", opisane su 4 skupine ispitanika: 1) bez donjih dišnih simptoma (DS); 2) bez gornjih i donjih DS; 3) bez DS i hiperreaktivnosti bronha s normalnim FEV1; 4) bez DS i hiperreaktivnosti bronha s normalnim FEV1, ukupnim IgE i s negativnim prick testom. Medijani pH-vrijednosti nisu se razlikovali između skupina (7,72; 7,73; 7,73; 7,73), ali uvođenjem sve strožih kriterija zdravlja uočen je blag, iako nesignifikantan, porast minimalnih pH-vrijednosti KI-a (6,95; 7,10; 7,20; 7,37). Medijan pH KI s interkvartilnim rasponom u ukupnom uzorku (7,72; 7,63 do 7,76) bio je unutar raspona vrijednosti izmjerenih u istraživanjima drugih autora. Na pH KI nisu utjecali spol, navika pušenja i atopijski status i nije bio povezan s dobi, vrijednostima FEV1 ili ukupnim IgE. Uočeni nesignifikantni trend porasta pH KI nakon uvođenja strožih zdravstvenih kriterija sugerira potrebu daljnjih istraživanja kriterija za definiranje zdravlja dišnog sustava na većem uzorku.