Humans express four distinct cell surface CD1 molecules, termed CD1a, b, c and d, which present lipid antigens to CD1a, b, c and d-restricted T cells respectively. Recent studies have suggested that many of these T cells recognise endogenous self-lipids, and comprise unique T cell populations that may constitute up to 10% of human peripheral blood T cells. However, their phenotypic and functional properties remain poorly defined. While CD1 tetramer technology has been successful in identifying and characterising CD1-restricted TCRs specific for defined, bacterial or synthetic lipid antigens, it is more difficult to detect CD1a, b, c and d self-antigen-reactive T cells, particularly when the identity of the antigens is unclear and/or their affinity is low. Here, we have produced mammalian CD1a, b, c and d tetramers containing endogenous lipid antigens, and identified and compared various methodologies to visualise and characterise human CD1-autoreactive T cells ex vivo. This is allowing us to detect some CD1-reactive T cells subsets amongst human PBMCs and to examine the phenotype and TCR repertoire of these cells. This work is an important step towards understanding CD1-reactive T cells in health and disease.