Paul Ehrlich and the Nobel Prize. The Construction of Scientific Excellence. From the first award in 1901 until now the Nobel Prize was and is valued as the highest recognition of the scientific community for the outstanding – excellent – scientific work of a researcher. And insofar, winning the Nobel Prize was a highlight in Paul Ehrlich's life. But from the first nomination in 1901 until 1908, when he was awarded the prize, it was a long way. Between these years (...) Ehrlich had been nominated 89 times by 80 scientists all over the world. The article sketches how excellence has been constructed by using the example of Paul Ehrlich. On the one hand, scientific networks are a precondition for being nominated by colleagues, on the other hand, excellence had been valuated and constructed in complex valuation processes and administrative procedures. The article presents first an overview over the nominations of Paul Ehrlich – who nominated him for what reasons? Moreover, the chapter sketches the relations between some nominators and Paul Ehrlich. After he had been nominated, the nominations were evaluated by members of the Nobel committee. The second part follows the complex procedures of evaluation to find the most excellent scientific work in accordance to Nobel's will. Finally, the Nobel Prize is embedded in broader network relations and the moral and relational economy of networks, which is exemplified by describing Paul Ehrlich relations to Carl Julius Salomonsen. (shrink)