In practice as well as in management research, process models are an important element of innovation management to standardize or describe innovation processes. The literature presents numerous process models, which are difficult to overlook. This raises several questions: What is the benefit of standardized innovation processes? Why are there different process models? Is there ‘one best way’? This chapter attempts to introduce people involved in innovation management to process models. With this purpose in mind, we give a brief review of the emergence and advancement of innovation process models in two parts of the world (the Anglo-American and German-speaking world), highlight pros and cons and discuss the implications for current innovation practice. In order to achieve this, we focus on models which had a significant effect on practice or research.