Recent interest has focused on interactions between natural killer (NK) cells and dendritic cells (DCs). In vitro and in vivo studies have demonstrated various effects of NK–DC interactions, including activation and cytokine production, maturation of DCs and NK-cell lysis of certain autologous DCs. These interactions are important during an immune response in vivo, however, it remains unclear where in the body NK cells and DCs might interact and whether observed in vitro crosstalk between these cell types happens in vivo. We propose evidence for at least two potential locations of in vivo interactions for human NK cells and DCs, including sites of inflammation and lymph nodes.