Mental disorder among childrenand adolscent are infrequently seen, yet they can be managed by trained primary care practitioners. The objectives of the study were - to assess the pre-test level of knowledge and attitude regarding childhood mental disorders among primary school teachers; to assess the post-test level of knowledge and attitude regarding childhood mental disorders among primary school teachers; to assess the difference of pre-test, post-test level of knowledge and attitude; to identify the relationship on post-test level of knowledge with attitude; to find association of post-test level of knowledge and attitude with selected demographic variables. The samples were selected by using purposive sampling technique. The data were collected through questionnaire and Likert scale, developed by the researchers. The collected dates were analyzed by using descriptive and inferential statistics and the findings showed that the majority of school teachers 47(78.3%) had adequate knowledge and 13(21.7%) had moderately adequate knowledge, while 42(70%) had positive attitude and 18(30%) had neutral attitude. The study finding showed that the level of knowledge and attitude of the primary school teachers improved after the planned teaching program. And there was no significant association between level of knowledge and attitude with the selected demographic variables like age, experience, marital status, disorder in family and place of residence. The study concluded that the structured teaching program can improve both knowledge and attitude level among primary school teachers on childhood mental disorders.