A combined RFLP and AFLP map was constructed for hexaploid oat (Avena spp.). The segregation of AFLP markers was scored in two hexaploid oat recombinant inbred line (RIL) populations, the 'Kanota' x 'Ogle' RFLP population, and a population derived from 'Clintland64' and 'IL86-5698', barley yellow dwarf virus (BYDV)-sensitive and BYDV-tolerant lines, respectively. More than 300 AFLP markers were scored in each population, of which 97 could be scored in both populations. AFLP markers were linked to RFLP markers in 32 of 36 'Kanota' x 'Ogle' RFLP linkage groups. The addition of the AFLP markers to the 'Kanota' x 'Ogle' RFLP data set combined markers from four pairs of linkage groups and increased the size of the map from 1402 cM to 2351 cM. Thirty linkage groups were observed in the 'Clintland64' x 'IL86-5698' population, two of which could be consolidated by comparing the maps from both populations. The AFLP and RFLP markers showed very similar distributions in the 'Kanota' x 'Ogle' population with a tendency of each type of marker to cluster with markers of the same type. The placement of a set of AFLP markers on the 'Kanota' x 'Ogle' linkage map will enrich the RFLP map and allow others to relate AFLP markers for agronomically important genes to the reference 'Kanota' x 'Ogle' linkage map.