Weinvestigate the problemof designingefficient multiplex PCRfor medical applications. Weshowthat the problemis NP-completeby transformation to the Multiple Choice Matchingproblemand give an efficient approximationalgorithm. Wedevelopedthis algorithm in a computer programthat predicts which genomicregions maybe simultaneously amplified by PCR.Practical use of the software shows that the methodcan treat 250 non-polymorphicloci with less than 5 simultaneousexperiments. Keywords.Multiplex PCR,diagnostic, heuristic algorithms, NP-completeness.