There is a need to clarify the role of the meniscus in knee OA which may be aided by the identification of biomarkers that reflect the molecular events involved in the tissue degradation. This is of particular importance in the early stages of the degenerative processes, a crucial phase when it might still be possible to interfere with disease progression before tearing and critical loss of meniscal function occurs. One way to achieve this goal is exploratory proteomics by mass spectrometry (MS), which has the potential to analyse the proteome of complex samples. Thus, our aim was to gain new knowledge about the molecular processes within the human meniscus by comparing the proteomic profiles of both the lateral and medial meniscus from healthy controls, subjects with mild signs of joint degeneration, and patients with end-stage knee OA, using a non-targeted MS approach operating in data-independent acquisition (DIA) mode. For the research purpose six groups were established: medial and lateral menisci from control donors (n=12), medial and lateral menisci from donors with mild signs of joint degeneration (n=13) and medial and lateral menisci from end-stage knee OA patients (n=12).