Background and aim Early detection and intervention can improve the treatment outcome of childhood mental disorders, and primary school teachers may play an important role in referring suspected cases to mental health facilities if they have good awareness and attitudes toward these disorders. The aim of this study is to assess the awareness and attitudes of primary school teachers toward childhood mental disorders in Taif, Saudi Arabia. Methods This is a cross-sectional study conducted among classroom teachers in primary schools in Taif, Kingdom of Saudi Arabia. It was conducted during the period from 2022 to 2023 in both public and private schools. An anonymous, self-administered, online questionnaire was used to assess participants' awareness and attitudes toward pupils with mental health issues. The collected data were analyzed using the chi-square test to examine the associations between various categories and the ANOVA test to compare means. Results The study included 417 teachers, 63.5% of whom were males, the mean of their ages was 39.59 years (SD±8.66), and the mean of their work experience was 12.8 years (SD±8.02) in different teaching specialties. Among participants, 60.2% claimed that no pupils had mental health problems in their classes, 80.1% had not referred any pupils to mental health facilities, and 88.5% did not receive any training related to childhood mental health problems. A humble percent (12.2%) of the participants claimed a good awareness of the signs and symptoms of childhood disorders. Only 54% of teachers advise visiting a psychiatric clinic in case of psychiatric problems, and a similar percentage of teachers believe that psychiatric drugs cause addiction. The male gender, being specialized in humanitarian subjects, having relatives or friends with childhood mental disorders, and receiving training related to childhood mental health were significantly associated with teachers' better awareness. Conclusion Primary school teachers generally lack awareness of childhood mental health and have underestimation and poor recognition of cases of mental disorders. There are many teachers who also have unfavorable attitudes toward psychiatric disorders, patients, and treatments, which requires much effort to improve their awareness and attitudes toward childhood mental disorders.