The transforming growth factor β (TGFβ) family of cytokines achieves homeostasis through a careful balance and crosstalk with complex signalling pathways. Inappropriate activation or inhibition of this pathway and mutations in its components are related to diseases such as cancer, vascular diseases, and developmental disorders. Quantitative imaging of expression levels of key regulators within this pathway using positron emission tomography (PET) can provide insights into the role of this pathway in vivo, providing information on underlying pathophysiological processes. PET imaging can also be used to study the drug targeting of this pathway and to detect diseases in which this pathway is disturbed. In this review, we provide an overview of PET tracers available to study the TGFβ signalling pathway. In addition, we discuss future imaging targets for this pathway and possible leads for new PET tracers.