Aim. To assess the prevalence of emotional and behavioural problems among preschool children. Method. The Disturbing Behaviour Questionnaire (DBQ), which was drawn up on the basis of the opinions of parents and educators, was completed by kindergarten teachers in the following categories: Excessive crying (Cry), Motor awkwardness (Awk), Lagging (Lag), Excessive dependence (Excdep), Developmental delay (Del), Hyperactivity (Hyper), Hyperactivity with aggression (Hypag), Aggression (Ag), Auto-aggression (Aag), Strange Behaviour (Strati), Self-Isolation (Isol), Avoiding Eating (Aveat), Avoiding certain foods (Avid), Overeat (Overeat), Compulsive eating (Compeat) using the following assessment scale: Absent; Very rare; Rare; Frequent; Very frequent; Always. Subjects. 961 children aged 3 to 7 years from randomly selected kindergartens from all districts of Krakow aged from 2.7 to 7.9 years (Mean: 5.4; SD 1.13). Results. Absent was noted in 108 (11.3%) of children. 270 (28%) children answered Always or Very frequent in at least one category, including: Cry 4.2%, Awk 4.3%, Lag 4.3%, Isol 3.1%, Hyper 11.6%, Hypag 3.0%, Ag 1.2%, Aag 0.2%, Excdep 3.5%, Del 1.2%, Stran 1.3%, Aveat 6.4%, Avfd 8%, Overeat 1.3%, Compeat 0.6%. On the overall DBQ and 6 categories (Awk, Lag, Hyper, Hypag, Ag, Del) boys had statistically significantly greater intensity of problems. In terms of correlation of items on the DBQ with age, 6 items were observed to have a statistically negative relation with age (Cry, Isol, Excdep, Aveat, Avfd, Awk) as was the overall scale. Overall scale, Cry and Excdep turned out to be significant for both genders, Ag, Aveat and Avfd for girls, Awk for boys. Discussion. A series of methodological and interpretational reservations and doubts need be taken into account when interpreting results.