Knowledge about various illnesses and their management is not satisfactory among high school students especially in rural areas in India. Various incorrect practices and myths associated with illnesses and injuries still exit. Training and education about correct management of injuries and illnesses for students is a sound and logical investment. A randomized controlled trial was undertaken among 120 students of ninth class (age group- 14-15 years) from a Government Senior Secondary School at Chandigarh, India. Students were randomly assigned to 2 groups (Group A and B) of 60 each using "blocked randomization process." Both groups were administered a pretested questionnaire for assessing their baseline knowledge, followed by on-the-spot demonstration the next day for assessing their skills. A training manual on 40 common childhood illnesses and injuries entitled "Swasthya Chalisa" (which means 40 health conditions) prepared with the help of the experts, was distributed to all study students. In addition, group A was also provided with on-the-spot demonstration training session. Post intervention evaluation of the level of knowledge and practices of both groups was done 15 days after the intervention. A scoring system was devised to quantify the knowledge and practices of students on first aid. Informed consent of the principal, teachers, students and their parents was taken before conduction of study. It was observed that students lacked knowledge in subject areas like management of uncommonly encountered illnesses in childhood (viz. T.B, Backache etc), emergency conditions (viz. CO gas poisoning, respiratory tract obstruction, epilepsy, unconsciousness, burns, food poisoning) and some routine day-to-day conditions which are not taken seriously for treatment (acne, epistaxis, food-poisoning, and constipation). The mean group scores for both groups (Group A and B) on combined knowledge and skills were higher at post-intervention than pre-intervention. Increase in level of knowledge from pretest to posttest was greater for Group B than for Group A by 33%. Also, increase in level of skills from pretest to posttest was also greater for Group B than for Group A by 135%. Overall knowledge and skills increased to 43% in group B as compared to A. It is concluded that there is a need for strengthening the knowledge of students regarding common illnesses and injuries by incorporating these training and education as a part of school curriculum. (Contains 3 tables.)