Studies conducted in India have shown poor mental health literacy (MHL) among teachers and there is the absence of a module to train the teachers on MHL. This study is thus undertaken to assess the MHL among teachers as well as to develop a module to train high school teachers on MHL and to test the effectiveness of the module on mental health literacy among the teachers. A mixed methodology will be adopted. In the quantitative component MHL and referral practices among high school teachers was  assessed through a school-based approach. A total of 145 secondary schools  formed the sampling frame with Udupi and Brahmavar blocks having 81 and 64 schools respectively. Stratified cluster random sampling technique was adopted where schools were stratified into government aided and private and then from each category the schools were selected using simple random sampling technique to achieve the required teacher population under each category calculated.   A total of 460 teachers were included for assessing baseline MHL. A qualitative study design was adopted to understand stakeholders’ perceptions regarding mental health disorders and remedial measures among adolescents. It included focus group discussions (FGDs) and in-depth interviews (IDIs) among teachers, parents and mental health and other health professionals. A training module was developed based on the information collected through the analysis of quantitative and qualitative data. The module was  reviewed and validated by a panel of experts. The final version of the module was developed after incorporating the suggestions given by the experts. To test the effectiveness of the module on MHL among the teachers, a parallel stratified cluster randomized controlled trial study design was employed. A total of 306 teachers were be randomly allocated into intervention and control group. The selection of the schools for the trial was based on responses on the case vignettes at baseline assessment.  Each school where 50% participating teachers are unable to identify at least two conditions appropriately on the case vignettes in the questionnaire were selected. A list of such schools were  prepared.  These schools will then be approached and invited to participate in the intervention. The schools were  randomized into intervention and control groups. The training were conducted for intervention group.  MHL was assessed before intervention and immediately post intervention and after six months among intervention group and baseline and after six months MHL was asssed among control group.  Changes in MHL between baseline and six-month follow-up  was assessed.