Purpose of review To describe how to better identify frail multiple myeloma patients and to treat them appropriately. Recent findings Proteasome inhibitors, such as bortezomib, carfilzomib, and ixazomib, and immunomodulatory agents (IMiDs), such as thalidomide, lenalidomide, and pomalidomide, have significantly improved the outcome of multiple myeloma patients in the last decade. However, both in clinical trials and in daily clinical practice, elderly multiple myeloma patients have shown lesser benefit. This is mainly due to less stringent use of proteasome inhibitors and IMiDs, increased toxicity, and subsequent early discontinuation of therapy in elderly. Summary Multiple myeloma typically affects elderly patients. Approximately one-Third of patients are older than 75 years at diagnosis. Moreover, at least 30% are frail, both due to disease-related symptoms and (agerelated) decline in physical capacity, presence of comorbidities, frailty, polypharmacy, nutritional status, and cognitive impairment. Treatment regimens that are investigated in clinical trials for transplant-ineligible patients have largely been investigated in fit, rather than frail patients, the latter being typically excluded or highly underrepresented therein. Data on the feasibility and efficacy of current standards of care are therefore lacking in frail patients. Preliminary data suggest a higher toxicity and discontinuation rate, loss of efficacy, and impaired quality of life in frail patients. Geriatric assessment helps to identify frail patients according to their functional and cognitive status. Both the International Myeloma Working Group (IMWG)-frailty index and Revised Myeloma Comorbidity Index constitute recently proposed algorithms that easily identify intermediate-fit and frail patients. Ongoing and future clinical trials, specifically designed for frail patients, will hopefully define frailty-directed treatment selection.