Uptake of Cd, Pb, Zn, Cu and Mn in two populations of Holcus lanatus was studied in a solution culture experiment in which Cd, Pb and Zn were supplied in factorial combination. Results show complex interactions between these three metals and their accumulation in non-tolerant plant shoots. In the non-tolerant population, most interactions are positive and thus tend towards increased metal concentrations. In the tolerant population, apart from a positive cadmiun-zinc interaction on cadmium concentrations, results are generally insignificant. It is apparent that single metal studies of non-tolerant populations should take into account these interactions, while studies of metal-tolerant populations should take into account that, in Holcus lanatus at least, tolerances to Pb, Zn and Cd are closely interlinked. The results confirm that in this population metal tolerance is related to decreased translocation of metals from roots to shoots. © 1979.