part of the Global Kidney Health Atlas (GKHA) project, a new initiative to assess kidney care in all world regions administered under the umbrella of the International Society of Nephrology (ISN), was to comprehensively examine the existing nephrology workforce in the form of the number of nephrologists and nephrology trainees; nephrology training capacity in terms of availability, duration, and structure; and the perceived shortages in health care providers pertaining to nephrology across all 10 ISN regions19 and 2014 World Bank country classification20 as low-, lower-middle–, upper-middle–, and high-income nations, based on the World Health Organization (WHO) building blocks.21 Results Response rate. Responses were received from a total of 125 of 130 UN member states (96% response rate) across 10 ISN regions, and 121 countries answered survey questions pertaining to nephrology workforce. Further details on the response rate and population coverage of the survey have been described elsewhere.22 Global density of nephrologists. Overall, the density of nephrologists reported was 8.83 per million population (PMP) (Table 1, Figure 1a). There was considerable variation in density of nephrologists among World Bank income groups and ISN region countries. High-income countries had the highest nephrologist density (28.52 PMP), followed by upper-middle–income (7.23 PMP), lower-middle–income (2.38 PMP), and-low income (0.31 PMP) countries (Table 1). Of the 10 countries with the lowest nephrologist density, 9 belonged to the Africa ISN region, and sub-Saharan Africa specifically. Yemen, in the Middle East ISN region, was the exception (Figure 1b). In contrast, the countries with the highest nephrologist density were from different ISN regions. Japan (North and East Asia region) reported the highest density, followed by Lithuania (Eastern and Central Europe region), Taiwan (North and East Asia region), Greece (Western Europe region), Uruguay (Latin America region), Spain (Western Europe region), Slovenia (Eastern and Central Europe region), Argentina (Latin America region), Germany (Western Europe region) and Oman (Middle East region) (Figure 1b). Overall, countries in the Africa ISN region reported a low density (3.64 PMP) of nephrologists (Table 1). The lowest numbers were reported from sub-Saharan countries, namely Malawi (0.06 PMP), Mozambique (0.08 PMP), and Ethiopia (0.09 PMP). On the other hand, the highest numbers were reported from North African countries, namely Egypt (21.65 PMP), Tunisia (16.31 PMP), Libya (12.48 PMP), and Algeria (11.38 PMP) (Supplementary Figure S1). Eastern and Central European countries reported a high density (16.33 PMP) of nephrologists (Table 1). However, there was wide variation in nephrologist density among the countries in the region. Turkey (6.30 PMP), Moldova (9.02 PMP), and Macedonia (9.54 PMP) reported the lowest densities of nephrologists, while Lithuania (69.34 PMP) and Slovenia (40.33 PMP) reported the highest, a difference of 63.04 between each end of the spectrum (Supplementary Figure S1). MA Osman et al.: Health workforce for nephrology care: existing manpower and training capacity review Kidney International Supplements (2018) 8, 52–63 53 In the Western Europe ISN region, countries overall reported a very high density (21.04 PMP) of nephrologists (Table 1). All countries in the region reported higher densities than the global average (8.83 PMP). Israel (9.69 PMP) reported the lowest density of nephrologists, while Greece (46.40 PMP) reported the highest (Supplementary Figure S1). In the Oceania and Southeast Asia (OSEA) ISN region, countries overall reported a low density (3.98 PMP) of nephrologists (Table 1). Within the region, Burma (0.37 PMP), Indonesia (0.43 PMP), and Laos (0.43 PMP) reported the lowest densities of nephrologists, while Australia (20.88 PMP), New Zealand (13.07 PMP), and Singapore (9.69 PMP) reported the highest (Supplementary Figure S1). In the North and East Asia ISN region, countries overall reported a high density (12.37 PMP) of nephrologists (Table 1). Japan (78.79 PMP) reported the highest density of nephrologists in the region and globally, followed by Taiwan (61.97 PMP), South Korea (18.32 PMP), Hong Kong (16.31 PMP), and Mongolia (15.04 PMP). Although China reported the highest absolute number of nephrologists globally (mean: 8500), it had the lowest density within its region (5.12 PMP) (Supplementary Figure S1). In the North America ISN region, both responding countries reported a density of nephrologists higher than the global average of 8.83 PMP: 17.81 PMP in Canada and 24.89 PMP in the USA (Supplementary Figure S1). Furthermore, the region reported the highest density (24.2 PMP) of nephrologists of all 10 ISN regions (Table 1). In the Latin America and Caribbean ISN region, countries overall reported a high density (15.23 PMP) of nephrologists (Table 1). However, there was wide variation among countries in the region, ranging from Guatemala (3.02 PMP) and Nicaragua (3.72 PMP) with the lowest densities to Uruguay (44.88 PMP) and Argentina (34.54 PMP) with the highest (Supplementary Figure S1). In the Middle East ISN region, countries overall reported a low density (6.17 PMP) of nephrologists (Table 1). Yemen (0.22 PMP), which had one of the lowest densities of nephrologists