Osteosarcopenia, an age-related degradation of bone and muscles, is a global concern that is associated with higher disability, morbidity, and mortality. Determining the best clinical method for assessing both muscle and bone is essential to identify older adults with osteosarcopenia. Early identification and diagnosis of osteosarcopenia will allow clinicians to initiate evidence-based prevention and treatment strategies to optimize older adults’ musculoskeletal health and prevent potential complications. This chapter focuses on clinical tools that are feasible and easy to implement in clinical settings to identify people with osteosarcopenia. We explain osteosarcopenia diagnostic algorithm starting with identifying older adults with risk factors for osteosarcopenia. Older adults with risk factors should be evaluated for their bone mineral density and screened for sarcopenia using the Sarc-F questionnaire. Measurement of muscle strength mass and physical performance should be implemented on patients at risk of sarcopenia. This algorithm will identify older adults with osteoporosis, sarcopenia, or osteosarcopenia. This chapter explores the clinical application of various measurement methods available for the assessment of muscle and bone in the diagnosis of osteosarcopenia.