The Ocean Health Index is a new method to define and quantify the health of the ocean in a comprehensive and integrated way. A healthy ocean is defined as one that can sustainability deliver a range of benefits to people now and in the future. The Ocean Health Index (the Index) tracks how countries are doing across a portfolio of 10 goals that people have for a healthy ocean. Countries can track how well they are doing for each of the 10 goals and across the goals that they have for a healthy ocean. Over time, the Index can be used to highlight areas of success or improvement. This paper summarizes some of the assumptions, methods and results of the first calculation of the index, released in the journal Nature in August 2012. At this level analysis focused on 171EEZs, belonging to 151 of the world’s coastal countries. This paper presents general information about the Index and the performance of the 10 Nairobi Convention countries (Comoros, French Indian Ocean Territories, Kenya, Madagascar, Mauritius, Mozambique, Seychelles, Somalia, South Africa and Tanzania) to explain why such an Index is needed and what it can be used for from the perspective of the member States of the region. Future application of the Index at a regional level will provide opportunities to use a finer scale, more comprehensive data than were used at the global level, and to develop regionally-relevant weightings for the 10 goals. Additionally modeling approaches that were made in the global analysis can be improved for regional level comparisons. The paper and discussions of the results will be used to gauge interest to conduct a regionally focused application of the Ocean Health Index for the Nairobi Convention region in 2013-14. This will culminate in an assessment of the usefulness of the index for the countries of the Nairobi Convention region to assess the health of their EEZs, inform future management and policies, and to increase the provision of ocean benefits to the citizens and coastal communities of the countries sustainably.