OBJECTIVES: Developing connections with other researchers in a network, learning informally through these connections and using them to reach goals, is expected to increase research capacity and strengthen performance. So far, this has not been empirically demonstrated. We assessed what and how network collaboration adds to development of researchers. DESIGN: Exploratory qualitative study using semistructured online interviews, analysed by inductive and deductive methods. For the deductive analysis, an existing value creation framework to study informal learning in networks was used and adjusted to our context. SETTING: The CanTest Collaborative-an international team of primary care cancer researchers working on early detection and diagnosis of cancer. PARTICIPANTS: Sixteen primary care cancer researchers. RESULTS: Connections with other researchers in an international network created diverse value cycles, where most outcomes were in the potential value cycle, acquiring knowledge, skills, social capital, resources and ideas. Not all potential value will be applied but many interviewees described realised as well as transformational value. In our context, the transformational value from the framework appeared to be related to other perspectives on the research process. Advancement of the network depends on opportunities, timing, role models and connections between different perspectives. CONCLUSIONS: Focus on the factors that are relevant for network advancement will support researchers in early detection and diagnosis of cancer research patients who participate in an international network and bring sustainable change in this domain. When, subsequently, researchers in the CanTest network bring about more realised and transformational learning outcomes, this will contribute to capacity development.