Objectives <p>The aim of this study was to assess the associations between ultrasonographic masseter muscle thickness, sarcopenia and Eichner Index in outpatients over 60 years of age.</p> Methods <p>Participants who admitted to a geriatric outpatient clinic of a university hospital were included in this study. Comprehensive geriatric assessments were recorded. The European Working Group of Sarcopenia in Older People 2 criteria were used to evaluate sarcopenia and probable sarcopenia. Masseter muscle thickness (MMT) was measured bilaterally by ultrasonography. The sum of the mean MMT values for the right and left sides was divided into two equal parts, and the average of these two parts was recorded as the average MMT (AMMT).</p> <p>Masseter muscle was grouped into 3 types according to band appearances. State of dentition was evaluated according to the Eichner index.</p> Results <p>&gt;Fourty-six participants whose median age was 73 were included in the study (19.6% probable sarcopenic, 30.4% sarcopenic). AMMT was significantly lower in those with high SARC-F scores compared to low SARC-F score group (p=0.041). AMMT, the distribution of Eichner groups, right and left masseter muscle fibriller types were similar in probable sarcopenia, sarcopenia and non-sarcopenic groups (p˃0.05). AMMT was significantly correlated with handgrip strength, appendicular skeletal muscle mass, calf circumference. Left-sided functional tooth units correlated positively with left MMT, whereas the Eichner index was not independently associated with sarcopenia. </p> Conclusions <p>Decreased MMT might be useful as a predictor of low appendicular skeletal muscle mass.</p>