Although there is a growing corpus of literature on teacher assessment capability, less has been written on sociocultural assessment leadership practices with its emphasis on shared capacity building. Expertize in sociocultural assessment that enhances student and teacher learning is an aspect of school leadership that can have a positive influence on teacher practice and student achievement. Research conducted with 38 principals is used to produce 16 dimensions of situated leadership for assessment capability. The article concludes with an argument for a sociocultural conception of situated leadership assessment capability which differs significantly to a clinical competence-based model of assessment leadership.