A substantial number of preschool children exhibit psychological symptoms that have an impact on their own and their families’ lives. The aim of the current study was to investigate the prevalence, stability and increase/decrease in emotional and behavioral symptoms and the resultant impairment at two assessment points at preschool age. The sample consisted of 1,034 children drawn from the general population with a mean age of 51 months at t1 and 72 months at t2. Parents completed the Strengths and Difficulties Questionnaire extended version (Goodman, J Child Psychol Psychiatry 38(5):581-586, 1997; Goodman, J Child Psychol Psychiatry 40(5):791-799, 1999). At t1, 6.9 % of the preschoolers had a total difficulties and 6.8 % a total impact score within the abnormal range. At t2, these scores were 5.7 and 6.2 %, respectively. We found moderate stability of symptoms. From t1 to t2, emotional symptoms and prosocial behavior significantly increased, while hyperactivity, conduct problems, peer problems and total difficulties decreased. The mean total impact score did not change. Boys showed higher levels of symptoms (except emotional symptoms) and impact, and lower prosocial behavior, than girls. Moreover, there was a significant time x gender interaction, with girls showing a larger decrease in hyperactivity/inattention and in total difficulties than boys. The stepwise multiple regression analysis revealed that the total impact score at baseline, male gender, conduct problems, hyperactivity and peer problems significantly contributed to the explained variance of the total impact score at follow-up. This is one of very few studies to examine the stability and change of psychological symptoms in a large community sample of preschoolers, assessed twice during preschool age.