The present invention is drawn to methods of making concentrated fibrinogen- and platelet-containing compositions. The concentrated compositions can be produced by adding a sufficient amount of a fibrinogen precipitating agent, such as protamine or other similar acting agent(s), and a platelet aggregating agent, such as ADP or other similar acting agents(s), to a platelet/fibrinogen containing fluid to cause the fibrinogen to form a fibrinogen precipitate and the platelets to for platelet aggregations. The fibrinogen precipitate and the platelet aggregates are collected by a collection technique, such as filtration, settling, centrifugation, etc., and are solubilized and deaggregated, respectively, in a liquid vehicle to form a concentrated fibrinogen- and platelet-containing composition. The concentrated platelet and/or fibrinogen compositions can be incorporated into systems for making fibrin glues, hemostatic sealants, platelet rich wound healants, and other wound treating compositions.