Establishing primary care research networks (PCRNs) makes it easier to conduct clinical trials and health services research in a general-practice setting. Since February 2020, the German Federal Ministry of Education and Research (BMBF) has sponsored the development of six PCRNs and a coordination unit throughout Germany, with the aim of setting up a sustainable outpatient research infrastructure to raise the quantity and quality of primary care.The present article describes the design of a PCRN in Dresden and Frankfurt am Main - SaxoForN - and explains its structure and how it operates. The network is a transregional alliance between the two regional PCRNs named "SaxoN" (Dresden/Saxony) and "ForN" (Frankfurt am Main/Hesse), both of which run transregional and local research projects. For this purpose, joint standards and harmonized structures, for example with respect to the data infrastructure, qualifications, participation, and accreditation, were agreed upon and implemented at both sites.A critical success factor will be whether and to what extent the standards and structures, as well as resource planning, can be designed sustainably enough to permit the PCRNs to carry out high-quality research over the long term. To achieve this, the PCRNs will have to attract new practices and build up lasting relationships with them, qualify the research practices in order to standardize processes as far as possible, and regularly document their basic information and healthcare data.