Driven by the need to deliver 43,000 new affordable homes annually, there has been a surge in new residential tall buildings over the last 10-15 years in London. Advocates claim they are necessary to cope with housing demand whilst critics argue high construction costs impact affordable housing contribution. Using primary data on over 850 planning applications referable to the Mayor between 2011-2020, this study examines whether new tall buildings in London provide proportionally less affordable housing and are less likely to be built than midrise typologies. Data collected includes the maximum height and type of development, location, typology and Mayoral decision date. Findings show that, on average, the proportion of affordable housing is lower in tall building applications than lower-rise typologies. This is particularly marked for applications over 30 storeys and those of a tower typology, whereas developments of 10 storeys or less achieve the highest proportion of affordable housing, particularly those in terrace or linear block typologies. The influence of location is marginal, but main land-use and decision date play the greatest role where the proportion of affordable housing has increased in recent years. Using data from the London Development Database (LDD), the completion rate of tall buildings was found to be lower than mid-rise developments. Overall, this study argues that high-rise typologies provide proportionally lower levels of affordable housing and are less proficient at delivering them. On this basis, it is recommended that planning policy in London recognise the influence of height and typology in the provision and delivery of affordable housing.