To verify myofunctional orofacial characteristics in young adults and to compare data on individuals with and without myofunctional complaints, aiming to identify the main myofunctional problems and differentiating them from characteristics that are common for this population, as well as to list items for myofunctional evaluation in this population. Cross-sectional study with 85 adult participants, aged between 19 and 39 years, selected through consecutive sampling at the Department of Speech, Language and Hearing Sciences of Universidade Veiga de Almeida. The participants were divided into two groups: G1 (comprising 50 individuals referred for orofacial myofunctional disorders) and G2 (comprising 35 volunteers without complaints). Descriptive evaluation of craniofacial structures of hard and soft tissues, kinesiology and mandible range of motion and functional patterns of breathing, chewing, and swallowing was applied. Three expert Speech-Language pathologists assessed all participants. Statistical analysis was done using χ2-test, Student's t-test, or Mann-Whitney test. The reliability level was 99%. A predominance of Angle Class I pattern of occlusions for G2 (p<0.0001) was found. G1 showed (p<0.0001) mandible movements with deviations and joint noises, amplitude reduction in lateral and protrusive movements, unilateral chewing, nonexpected muscle contraction, temporomandibular joint noises, swallowing with excessive contraction of the orbicularis oris muscle, loud noise, and residues (p=0.006). The main myofunctional orofacial alterations in young adults with complaints refer to changes of the mandibular movements and patterns of chewing or of swallowing, reflecting the main items of the clinical evaluation. Many items of assessment and characterization do not differ between the groups, and these should be analyzed regarding their relevance.