To provide a process for producing a medical pressure-sensitive adhesive by which a high-molecular-weight medical pressure-sensitive adhesive having high cohesive force and excellent pressure-sensitive adhesiveness can be supplied stably with small dispersion and to obtain a high-molecular-weight medical pressure-sensitive adhesive having high cohesive force and excellent pressure- sensitive adhesiveness.

This production process comprises solution-polymerizing a monomer composition based on an alkyl (meth)acrylate in the presence of a radical- generating initiator desirably under conditions in which the content of dissolved oxygen of the polymerization system is equal to a degree of saturation of 5%, and the polymerization is performed in a sealed state. The adhesive comprises an acrylic (co)polymer having an average-molecular weight of 800,000 or above and obtained by this process.