The International Organization for Standardization recently responded to a growing global interest in cities by developing an index for measuring urban sustainability (ISO 37120). We address how well this standard applies to Arctic cities, and potential modifications that might improve its performance. After briefly discussing the goals of sustainability indicators, we examine the extent to which Arctic cities’ remote location, cold and changing climate, and thin, largely resource-based economies may create different sustainability challenges. We then critically examine the content of ISO 37120 and the context in which it was created. We place the index within a broader discussion of urban sustainability indicators and examine the extent to which it really addresses sustainability. We then analyze how well the ISO 37120 accounts for the characteristic features of Arctic cities that produce unique sustainability challenges. Our findings show that only half of ISO 37120′s 128 indicators actually measure future-oriented concerns. We suggest that, while the ISO 37120 may be a useful starting point in quantifying Arctic urban sustainability, the index should only be used as a foundation for a more in-depth analysis. To better represent Arctic cities, the ISO 37120 would need to include indicators that situate cities within their regional contexts, addressing both remoteness and the underlying basis of the Arctic city economy. The index should also measure the role of Indigenous populations, and chart the extent to which cities are working to increase levels of sustainability.