The results of field experiments in 1983/84 and 1984/85 were used to test the hypotheses (i) that cultivars and management systems which result in high biomass of winter barley will also produce high grain yield and (ii) that greater uniformity of tiller and ear size is associated with greater yield. In a set of cultivars, grain yield per plant was significantly correlated with biomass per plant despite no correlation with any individual yield component. Biomass per shoot was significantly correlated with grain yield per shoot. Treatments to increase shoot uniformity (the mass of individual tillers relative to that of the main stem) generally increased biomass per shoot and grain yield per shoot. The re-examination of data in the literature where yield and biomass were available confirmed the association of biomass and grain yield both on a per plant and per shoot basis. It is argued that harvest index is not a character which can be easily targeted for manipulation by growers, whereas crop management systems to increase biomass should be easier to specify.