Nature within cities provides benefits for people known as urban ecosystem services. An assessment of urban ecosystem services is growing in South America, a biodiverse and highly urbanized region. To synthesize this growing body of knowledge in South America, we performed a systematic review identifying patterns in the literature and knowledge gaps. Our review shows that Brazil, Chile, and Colombia contribute the greatest number of studies. More than 80% of the studies were published in the last five years, revealing this as an emerging research topic in the region. More than half of the studies had an environmental perspective and focused on services provided by green spaces. Nearly all studies involved regulating services, followed by cultural services. We found clear knowledge gaps, including a paucity of assessments on supporting and provisioning services, as well as the lack of studies in several countries, evaluations concerning land cover other than parks, and large-scale assessments. Comparing ecosystem services in different planning scenarios is urgently needed to make informed decisions, aid nature conservation, and provide ecosystem services for all urban dwellers. This knowledge will contribute to achieving sustainable cities and equitable access to ecosystem services in South America.