Objectives:
The article is the second part of the study aiming to describe the role of a speech-language therapy in protecting mental health of children. It concerns the competences of a speech-language therapist in a specialist team, speech and language assessment, diagnosis, and therapy.

Methods:
The research has an exploratory character. The secondary qualitative analysis of archive data collected from my SLT practice with preschool age children was used.

Results:
The speech-language therapist’s competences include speech, language and communication disorders diagnosis and treatment, as well as preventing these disorders. Skills in responding appropriately to the child’s current mental state are essential. The most common disorders in people with mental disorders include language, communication and prosody disorders, as well as psychogenic voice and swallowing disorders. The speech-language diagnosis can contribute to the early detection of mental disorders and can be used in differential diagnosis and in the recognition of unclear mental states. Therapy should be individualized properly organized, programmed, and balanced to meet the actual needs of children. Moreover, therapy has an additional preventive value, because efficient use of language has a positive impact on mental health.

Conclusions:
Speech-language therapists play an important role in protecting mental health of children. SLT for children who experience mental health problems has its own specificity. The results of speech-language assessment and diagnosis can be used in the process of diagnosing mental disorders. The positive effects of SLT can significantly improve the quality of life of the child and his family, and contribute to the prevention of mental health problems.