Objective: : This study investigated the validity and reliability of logopedic assessments of tongue function. Materials and Methods: : At two practices for myofunctional therapy, diagnosis of tongue dysfunction according to Kittel (1984, 1996, 2008) was carried out in 52 subjects (aged 5 to 63 years) by three speech pathologists at each practice. Results: : The agreement of the logopedic assessments was mostly satisfactory at one of the two practices but was unsatisfactory in most cases at the other practice. Conclusion: : The inconsistent agreement between the logopedic assessments does not permit a definitive statement about the actual clinical situation.