In Germany, it can be observed that schools increasingly take advantage of experts from the outside in their further pedagogical and organizational development. Regarding their profession and the area of content to which they are assigned, these experts represent a heterogeneous group. This contribution assumes that several patterns can be observed that have to do with the professional background of the consultants as well as with the content and the way these consultants work. It takes up insights from a larger research project conducted in the German state of North Rhine-Westphalia from 2009 to 2012. The project's findings were gained by means of a standardized survey of 957 school administrations and case studies at six schools with standardized interviews of teachers (20-87 per school), qualitative interviews with school administrations and teachers (5-8 per school), as well as document analyses on the design, the process and results of the external consultation of schools. The results indicate that there are two different types of consultation: the consultation of the entire teaching staff in the area of teaching development with a consultant who is directly connected to the school system (type 1), and a consultation of subgroups of the teaching staff in the area of organizational and personnel development with a consultant from outside the school system (type 2). This contribution provides new insights into a field that has in the German speaking context so far not been well researched.