We present a joint linkage analysis of eight data sets collected for asthma. Three of the data sets are full genome scans, while the remaining five concentrate on a 40-cM region on chromosome 5. We perform the analysis using one qualitative and one quantitative phenotype: asthma status and IgE level. Considering all data sets simultaneously, we do not find evidence for linkage to asthma affection status beyond the level expected to occur by chance twice per genome scan. In contrast, we observe significant linkage to IgE level on chromosome 6.