Given the situation where effective guidance of preschoolers with problem behaviors is urgently needed, the present study aimed to investigate kindergarten teachers' current status of guiding children with problem behaviors, and their awareness of necessity of and needs for in-service education to better guide children with problem behaviors. Through this investigation, the study tried to help better designing of a future in-service education for teachers in this matter. Two-Hundred-and-seventy-five kindergarten teachers in Seoul metropolitan area completed questionnaires measuring teachers' current status of guiding children with problem behaviors, past experience with in-service education to better guide children with problem behaviors and awareness of necessity of and needs for in-service education in this regard. The study found that kindergarten teachers have more children with externalizing than internalizing problems in their class, and are more aware of the nature and negative influence of externalizing problems than of internalizing problems. With regard to dealing with child problems behaviors, teachers were found to experience high levels of difficulties but moderate levels of satisfaction and self-confidence. Teachers reported to rely mostly on consultation from colleagues when encountered with difficulties guiding problematic children and utilize workshop/education opportunities provided by government to develop their skills. More than half of the teachers denied having attended an in-service education to better guide child with problem behaviors. However, almost all teachers endorsed the necessity of in-service education in this regard and their willingness to attend those. Lastly, teachers needed future in-service educations to focus on topics such as behavior modification and effective teacher-child/ teacher-parents communication, to rely on the methods including case studies, practices, roleplays, and coaching, to be taught by professionals in the field of child psychotherapy, and to be arranged in a way that it lasts for a certain amount of time and at the same time it does not give a lot of burdens to teachers' time and work. Implications of the results to designing future in-service educations were discussed and recommendations for future studies were made.