Sexual knowledge, attitude and behavior of primary and secondary education school studentsThis survey aimed to explore knowledge, attitude and behavior of primary and secondary education school students. The sampled population was the students from "pathom" or "po" 5 (late primary school-about 11 years old) through "matayom" or "mo" 6 (late secondary school-about 18 years old) at Phanomphrai district, Roi-Et province, Northeast of Thailand, in academic year 1999. The subjects were stratified into 3 groups, according to education levels, i.e. po 5-6, mo 1-3 and mo 4-6. Two multiple-choice questionaries were, after approved by 4 experts in sexology and in education, used separately, one for po 5-6 and another for mo 1-6 group, for quantitative survey. Three discussion guidelines were developed and used for each group. Among a total of 5956 students, 1073 (18.0) : The result of attitude towards who is the most suitable for teaching sexual education reveals that most po 5-6 group prefered a doctor or a nurse. This result corresponds to mo 1-3 (62.1%, 95%Cl: 55.2-69.0)and mo 4-6Z56.9%, 95%Cl:51.5-62.2), and 62.5%Z95%Cl: 58.8-66.3) of all students think so.The attitude towards should school reproductive health services be provided, survey only among mattayom students (mo 1-6), reveals that 53.2 % of mo 1-3, 59.2 % of mo 4-6 and 56.1 % of all mattayom students did not agree. On the other hand, 18.0 % of mo 1-3, 23.6 % of mo 4-6 and 20.7 % of all mattayom students agreed. Most of the students agree that counselling clinic in school by a doctor or nurse or health personnel would be most suitable (64.1 %, 95%CI: 60.5-67.7). The attitude towards what to do first if unwanted pregnancy occurs, survey only among mo 1-6, reveals that 49.7 % of mo 1-3 group would tell their parents and 25.5 % would consult a doctor or a nurse. The same attitude was found among mo 4-6 group, 58.6 % would tell their parents and 23.0 % would consult a doctor or a nurse. For the total of mo 1-6 students, 54.0 % would tell their parents and 24.3 % would consult a doctor or a nurse. The sexual experience was 1.1 % among po 5-6 students, 1.1 % among mo 1-3 and 5.2 % among mo 4-6, and the overall experience was 2.4 %. This study suggests sexual education in school be adjusted according to the student needs. School reproductive health services by means of counselling clinic may be appropriate and there should be a survey for parental readiness in counselling an adolescent with unplanned pregnancy.