The demographic and economic transition that many developing countries, including Jordan, are undergoing is producing important changes in diet and lifestyle that greatly impact the development of chronic illness. The health behavior of adolescents in developing countries constitutes one of the most serious global challenges we face. The purpose of this study was to explore the wellness appraisal of Jordanian adolescents. It specifically describes the (i) self-care and health history pattern, (ii) to assess physical activity and nutrition appraisal, (iii) quality of life appraisal and (iv) school and outside activities appraisal. A self-administrated questionnaire collected the data from adolescent groups (boys and girls.). A multi-stage stratified random sample was obtained from six public schools by first selecting the educational directorate located in the city of Irbid, which is located in the north of Jordan. A random sub sample of six individual schools was then selected. Individual classes were then selected. A total of 269 boys and 261 girls (12–17-year old) were included in the analysis. The results showed that the students engaged in risky health behaviors which could lead to short- and long-term health problems. The most alarming finding of this study was students’ nutritional habits, including less than the daily requirements of fruits, vegetables, milk and meat, while the intake of fast food, soft drinks and sweets were higher than recommended. School-based health promotion and wellness programs should be established in Jordan to influence the health behaviors of adolescents and parents and to avoid further deterioration of their health. Jordanian school curriculum needs to integrate more precise health education programs about diet, exercise, self care and other life style behaviors. More detailed studies are needed with more elaborate instruments about food habits, physical activities and psycho social life.