There has been limited epidemiologic information concerning preschoolers' behavioral and emotional problems in Eastern societies. This study was therefore aimed to investigate behavioral and emotional problems in a large sample of Taiwanese preschoolers using the Child Behavior Checklist for Ages 1.5-5 (CBCL/1.5-5). The CBCL/1.5-5 was scored by mothers of 645 Taiwanese preschoolers aged 24-71 months. Psychometric features of the scale as well as the raw scores and prevalence rates of behavioral problems of Taiwanese preschoolers were compared with those of American counterparts. Several demographic variables with the Total Problems and syndromes scores were also examined. The CBCL/1.5-5 was found to have good to excellent levels of reliability (internal consistency, test-retest reliability and inter-parent agreement) and an acceptable model fit of seven-syndrome factor structure (root mean square error of approximation = 0.055) when used with Taiwanese preschoolers. The prevalence rate of Total Problems, Internalizing syndrome and Externalizing syndrome score in the clinical range was 25.1%, 11.2% and 25.4%, respectively. Cross-cultural comparisons showed that Taiwanese preschoolers had higher scores in six narrow-band syndromes (effect size d=0.17-0.43, all p's