The concept of multimorbidity has risen in popularity over the past few years. It is use has led to, or coincided with, an increased recognition that patients often have more than one health problem which should not be treated in isolation. The motivation for more holistic, person-centred care that lies behind multimorbidity is to be welcomed. The 2016 National Institute for Health and Care Excellence multimorbidity management guideline helpfully makes recommendations in key areas that are important in the care of patients with complicated medical problems.However, we question the sustainability of the term for the following four reasons: (i) it is doctor and researcher centred rather than patient centred, focusing upon the number of diagnoses rather than the patient's lived experience, (ii) it is not a positive term for patients and is at odds with the move towards promoting active and healthy ageing, (iii) its non-specific nature means it holds little value in daily clinical practice and (iv) most definitions apply to a large segment of the population making it of limited use for health care planners. We argue that the complementary concepts of complexity and frailty would fit better with the delivery of patient centred care for people with multiple co-existing health problems and would be more useful to clinicians, commissioners and researchers.