Health inequity refers to the existence of unnecessary and unfair differences in the ability of an individual or community to achieve optimal health and access appropriate care. Kidney diseases, including acute kidney injury and chronic kidney disease, are the epitome of health inequity. Kidney disease risk and outcomes are strongly associated with inequities that occur across the entire clinical course of disease. Insufficient investment across the spectrum of kidney health and kidney care is a fundamental source of inequity. In addition, social and structural inequities, including inequities in access to primary health care, education and preventative strategies, are major risk factors for, and contribute to, poorer outcomes for individuals living with kidney diseases. Access to affordable kidney care is also highly inequitable, resulting in financial hardship and catastrophic health expenditure for the most vulnerable. Solutions to these injustices require leadership and political will. The nephrology community has an important role in advocacy and in identifying and implementing solutions to dismantle inequities that affect kidney health. Kidney disease risk and outcomes are strongly associated with inequities that occur across the entire clinical course of the disease. The authors of this Review describe the different inequities that affect kidney health and care worldwide, and consider potential solutions to help to mitigate these. Key points: Insufficient investment across the spectrum of kidney health and kidney care (from raising awareness of kidney disease, to its prevention, diagnosis and treatment) is a fundamental source of inequity, and affects all people at risk of, or living with, kidney diseases. Social and structural inequities are major risk factors for, and contribute to, poor outcomes for individuals living with kidney diseases. Access to essential diagnostics and medications for kidney disease is inequitable and insufficient, as are programmes to track their burden; these insufficiencies disadvantage patients in low- and middle-income countries from early in their disease course. The ability to access kidney care across the spectrum of disease without exposure to financial hardship is very inequitable; this inequity results in vastly different outcomes and life courses for patients who have the same diseases but live under different circumstances. Novel therapies for rare (orphan) diseases are often only available at extremely high prices; their use in children is often not adequately documented and the cost of these medications exacerbates inequities. All nephrology professionals should become skilled at advocating on behalf of their patients to communities, policy makers, administrators and insurers to develop constructive strategies and collectively reach optimal solutions to improve equity in the accessibility of quality kidney care locally and across the globe. [ABSTRACT FROM AUTHOR]