This article explores the role of place managers in controlling drug and disorder problems on 100 street blocks in Oakland, California. We use self-reports from a sample of place managers to explore their role in changing the social and physical conditions of street-block activity within the context of a randomized field trial in Oakland. On-site observations of the changes in the social and physical conditions of 100 street blocks were conducted and used as our outcome measures. Our results suggest that street blocks where place managers engaged in collective crime control activities had significantly fewer signs of disorder and greater levels of civil behavior. Our results also show that community cohesiveness on a street block was associated with fewer males selling drugs.