Cu^I-catalysed coupling of arylboronate esters with aryl and heteroaryl iodides and bromides is described. The transformation affords products in good yields using 5–10 mol% catalyst loadings. The described reaction requires a P,N-based bidentate ligand in combination with CuI for aryl–aryl coupling, but it proceeds without external ligands for aryl–heteroaryl coupling to afford the products. The reaction protocol can also be applied to achieve biarylation of diiodoarenes in reasonable yields.