SummaryPure red cell aplasia (PRCA) is an uncommon disorder, many cases lacking a well defined aetiology. This report describes three cases of PRCA (two idiopathic and one associated with B‐CLL) who were investigated to assess the possibility of their PRCA being associated with a clonal proliferation of T‐lymphocytes. The results show that one patient had evidence of T‐cell receptor (TCR) gamma chain rearrangement, and the other had a TCR delta chain rearrangement. These two cases raise the possibility of PRCA being associated with a clonal proliferation of T‐cells and further studies are wa