Most students are reported to be dissatisfied with their height and weight. The current study was designed to assess the prevalence of height and weight dissatisfaction and specific height-gain and weight-control attempts in school-children in Korea. A questionnaire survey was carried out in 3,382 students aged 11-18 years. The prevalence of dissatisfaction with height and weight was significantly higher in girls than in boys. High school students were more dissatisfied with their height and weight than elementary school students. The concordance rates between perceived vs actual height and weight were 30% and 45%, respectively. The average desired adult height was 8-9 cm taller than the average Korean adult height. The average desired adult weight was 4.9 kg more in boys, and 4.8 kg less in girls, than the current average Korean adult weight. Approximately 4.4-7.3% of overall school-children had tried to promote their growth. The prevalence of height-gain attempts was highest in middle school students, and the prevalence of weight-control attempts was highest in high school students. Among the height-gain methods, herbal medicine was most frequently used (46.4%), followed by growth-promoting health supplements (27.4%) and growth hormone (3.2%). For weight control, exercise at a fitness center was more favored (54.5%) than herbal medicine (17.5%) or diet drugs (13.0%). In conclusion, the prevalence of height and weight dissatisfaction was high and many students made attempts at height gain and weight control. These data emphasize the importance of health education about body image to students.