Sex work is defined from a liberal-feminist view as the negotiating and provision of sexual services by adults in return for payment. In Switzerland, sex work is basically legal and tolerated. The present study does not problematize the nature of sex work. It is considered here as a form of gainful employment rather than deviant behaviour, sexual risk behaviour or violence per se. In a qualitative study using problem focused guided interviews, 13 managers of brothels and contact bars in a Swiss city were questioned about their organizing of work, about working conditions, violence and its prevention. The content analysis of the data (Mayring, 2007) generated a manager typology (based on Kelle and Kluge, 1999). The results project four manager types: (I) collegial all-rounders who run small establishments; (II) co-operative managers of medium-size commercial premises; (III) authoritarian managers of medium-size and large brothels or contact bars and (IV) self-sacrificing managers of medium-size brothels. In respect to violence, these four types are characterized by association with differential degrees of potential risk for sex workers. While types I and IV can be classified as more risky in relation to violence and safety due to their specific characteristics, types II and III are clearly less dangerous for the sex workers. All the managers have introduced protective measures to prevent violence, yet they do not have a specific (explicitly formulated) strategy. In conclusion, the study shows that structural basic conditions and specific organizational working conditions impact on the risk of violence.