A flexible multi-chamber container for preparation of medical mixed solutions comprises at least three chambers (20. 21. 22) separated from each other by leaktight seams (27. 28. 29). The chambers being designated to be filled with different solutions are separated from each other by leaktight seams. At least a part of the first leaktight seam is provided with a separation zone to be opened for fluid transfer from the first into the second chamber and at least a part of the second leaktight seam is provided with a separation zone to be opened for fluid transfer from the second chamber into the third chamber. The leaktight seams are arranged and the separation zones are formed such that, in use of the container, for preparation of the medical mixed solution, the first separation and second separation zones are opened in a sequential order. Since the first zone is opened before the second separation zone will be opened the components are mixed one after another in a predetermined sequential order.
