A process for the preparation of PVP-iodine by reacting polyvinylpyrrolidone powder with elementary iodine at from 70.degree. to 100.degree. C. The reaction is carried out in the presence of formic acid, oxalic acid or an ammonium salt or amide of carbonic acid, formic acid or oxalic acid. The process avoids the disadvantage of long periods of heating, which can result in degradation of the polyvinylpyrrolidone, and is particularly suitable for the preparation of a stable PVP-iodine using a low molecular weight polyvinylpyrrolidone.