A key question facing planners is how to design new and develop existing urban environments to improve the social health of older adults, and consequently improve their overall health and wellbeing. Unfortunately research relating to the influence of the environment on the social health of the elderly lacks a clear definition of 'environment'. As a result the differing impacts of environment, however defined, on social health are not fully understood. This is an increasingly important area of research given the world's ageing population. This paper offers a critical review of the environment literature, with a specific focus on the how the physical, social, and policy dimensions of the environment influence the social life of the elderly; social life being an important component of social health. The paper investigates multiple environmental factors at different levels of influence on social life. It also provides a clear classification of environmental features that enable or inhibit social life. Drawing on the literature reviewed, there are manifold associations between physical, social, and policy environmental determinants of social health which need to be understood and prioritised. Developing age-friendly cities, where elderly people are socially active, results from a complex interplay of all of the determinants. This paper identifies the major gaps in current literature in this field and concludes with discussing key policy implications for planners. It offers areas for further research to improve the social health of the elderly through design of the urban environment.