OBJECTIVES: Sarcopenia is diagnosed on the basis of skeletal muscle mass and muscle strength/function; however, simpler and more accurate measures for muscle mass and muscle strength/function should be explored using ultrasonography. This study aimed to investigate a new screening method using ultrasonography to diagnose sarcopenia of lower leg muscles in older males. DESIGN: Cross-sectional study. SETTING AND SUBJECTS: A total of 60 males, aged 65 years or older, participated in this study. MEASURES: The muscle thickness (MT) and echo intensity (EI) of the lower leg muscles were measured using ultrasonography, and the physical functions were examined. The MT and EI values of the lower leg muscles for predicting low appendicular skeletal muscle mass index (ASMI) and low grip strength were analyzed using receiver operating characteristic curve analysis and significant cutoff values were observed. A binary logistic regression analysis was performed with an MT below the cutoff value or an EI above the cutoff value as the independent variable, and with sarcopenia according to the Asian Working Group for Sarcopenia criterion as the dependent variable. RESULTS: Using the optimal cutoff points of MT and EI for predicting a low ASMI and low grip strength, the MT of the tibialis anterior (TA), the EI of the TA and gastrocnemius, and the MT/EI index of the TA and soleus were found to be associated with sarcopenia after adjusting for age, body mass index, calf circumference, presence of diabetes mellitus, and statin use in the binary logistic regression model. In addition, the combined MT and EI of the TA showed predictability with respect to sarcopenia. CONCLUSIONS/RELEVANCE: Ultrasonographic assessment of lower leg muscles might be useful as a convenient approach for detecting sarcopenia. In particular, the determination of both MT and EI of the TA should be considered as an alternative method of screening for sarcopenia.