Classical linkage programs analyze the segregation of two markers in informative families. When several markers are available for one human chromosome, pairwise analysis can exclude linkage between each marker and an inherited disease. The identification of restriction fragment length polymorphisms has made many new informative markers, assigned to chromosomes, available. We have adapted the multipoint linkage program MLINK developed by Lathrop et al. in order to exclude linkage between cystic fibrosis and several markers known to be on human chromosome 4. The exclusion obtained is greater than that for a pairwise analysis.