Phase equilibria and miscibility in the silicon-rich corner of the system Si–Cu–Co were analyzed in the present work. Powder mixtures of Cu, Co and Si at 1400 °C were molten and slowly cooled to RT. At the resulting samples, the miscibility of silicide phases was found to be limited: ≤0.5 at% Cu in CoSi2, 1.5 at% Cu in CoSi and 3 at% Co in Cu3Si. Furthermore, a ternary phase Cu3CoSi2 was detected in the region of intermediate Si contents.