In cooperation with:

Kassel Stuttering Therapy for Adolescents & Adults

Treating stuttering with success since 1996

We specialize in stuttering therapy

The Kassel Stuttering Therapy (KST) Institute offers intensive online courses with a holistic concept and structured aftercare. For adolescents from 13 years and adults, the 6 month program is conducted exclusively by qualified therapists who are specialized in stuttering therapy. It is an international online program in English language – based on a mix of group and individual therapy in combination with a specific speech therapy software that can be attended anywhere in the world.

The unique KST stuttering program has been awarded the „Medical Management Prize“, the renowned „dfg-award“ and the prestigious „E-Health Award 2022/23“. The whole course can be done completely from home, including the necessary initial diagnostics.

The right stuttering therapy from
any place in the world:

The Kassel Stuttering Therapy:
Speak fluently, live freely!

For those affected, stuttering can be an extremely problematic speech flow disorder. It shapes every day, lowers the quality of life and often limits both professional and personal potential.

Idea and Founding of the Stuttering Therapy

The Kassel Stuttering Therapy was founded by Dr. Alexander Wolff von Gudenberg in 1996. He is himself an affected person and went through 12 stuttering therapies in various countries over almost 20 years. During this time, he made the decision to become a physican himself and to found his own institute in order to help stuttering people as effectively as possible. He formed the KST program based on the most successful therapy elements he experienced during his own therapy journey. Today the Kassel Stuttering Therapy Institute is an internationally-renown organization for people who stutter looking for professional support in overcoming their speech disorders.

Successes of the Kassel Stuttering Therapy

More than 4,500 stuttering persons have been treated with the Kassel Stuttering Therapy program. In 2022 Dr. Wolff von Gudenberg was honored with the Silver Commemorative Plaque by the Hessian State Medical Association in Germany for his long-standing, successful work in the field of stuttering.

Worldwide, only very few therapy programs can show as many long-term studies with such high evidence as the Kassel Stuttering Therapy.

Prof. Dr. Harald Euler, University of Kassel

Success in numbers

The results of the Kassel Stuttering Therapy have been analysed and evaluated by independent scientists right from the beginning: 93% of patients show significant improvements immediately after therapy, 89% still one year after therapy, and 75% of patients continue to benefit even 3 years after the end of therapy program.

In particular, the long-term and thus sustainable success is crucial for us, as only this brings a real increase in quality of life.


Spontaneous success


Sustained success


Lon-term success

Fig. 1: Objective stuttering data: Percentage of syllables stuttered (count) for adults and adolescents across three measurement points.1

Fig. 2: Subjective stuttering data: Ratings of negative emotions for adults and adolescents over three measurement time points.1

Fig. 3: Long-term significant improvement in speech avoidance, objective incoherence and subjective stuttering ratings over 3 years for adolescents and adults.2

Fig. 4: Long-term significant and sustained improvement in objectively measured fluency (counting of syllables) over the course of 5 years.2,3

1Harald Euler et. al., Kann eine methodenintegrierende globale Sprechrestrukturierung negative Emotionen mindern? Logos, 2016, 2:

2Harald Euler et. al., Computergestützte Therapie bei Redeflussstörungen. Die langfristige Wirksamkeit der Kasseler Stottertherapie. Sprache·Stimme·Gehör, 2009, 33: 193 – 201.

3Bernadette Talartschik, Stottern und das Konzept der Kasseler Stottertherapie. forum HNO, 2014, 16: 138-144.

And this is what our clients say about stuttering therapy:

I will never forget the difference between the day I arrived there a little nervous and the incredible moment of confidence after the intensive course knowing that I had found a way to manage my stuttering problem.

Felix K.

The group dynamics in the classroom course were a great experience for me. We grew together incredibly and became friends; I still meet up with some of them today – three years later.

Birgit A.