The present study was performed in order to analyze whether T‐cell receptor (TCR)/CD3 assembly, intracellular transport and surface expression are carried in a similar way in αβ‐and γδ‐T cells. By means of optimal immunoprecipitation conditions with ³⁵S‐methionine/cysteine‐ or biotin‐labelled TCR/CD3 proteins from αβ‐ or γδ‐T‐lymphoma‐cell lines, as well as TCRγδ cDNA transfectants, it was found that CD3δ chains associate less strongly with TCRγδ heterodimers compared to TCRαβ heterodimers. This preferential reactivity of CD3δ chains appears to be structural and not owing to differences in γδ‐ versus αβ‐T‐cell intracellular environments. Our results are in accordance firstly, with data from CD3δ‐deficient mice, which have γδ‐T cells but no αβ‐T cells, secondly with the suggested role of CD3δ chains in the positive selection of αβ‐T cells, a process apparently not followed by γδ‐T cells, and lastly with the differential roles of CD3δ chains versus CD3γ chains, explaining the maintenance of two CD3δ and CD3γ genes after the duplication from a CD3δ/γ gene present in avians. The impaired reactivity of CD3δ chains with TCRγδ heterodimers seems to be owing to a less efficient association with TCRγ chains. In contrast, CD3δ chains interact as strongly with TCRδ chains as do CD3γ chains with both TCRγ and TCRδ chains. These data may explain, at the molecular levels, why surface TCR/CD3 expression levels are impaired in γδ‐T cells from CD3γ‐deficient mice but not from CD3δ‐deficient mice.