The mixing device for producing ready-for-use medical flush solutions, particularly for hemodialysis concentrates, comprising a source of ultrapure water which is connected via a supply line to a recirculation circuit in which a pump is disposed, comprising a computer and comprising a secondary-mixture connection line which is connectable to a feedstock container which prior to the beginning of the mixing operation contains powdery and/or granulated and/or slurried feedstocks that are to be mixed with the ultrapure water, is characterized in that a mixing venturi tube with its convergence chamber and its divergence chamber and a mixing valve are disposed in the recirculation circuit in flow direction one after the other.
