Rapid and informative ABO genotyping has become increasingly popular in forensic use. Seven differently fluorophor-labeled displacing probes for O1(261delG), A (261G), A (796C/803C), B(796A/803C), O2 (802G greater than A), A2 (1059delC), and A2 (1009A greater than G) were combined in one or two PCRs to determine either ABO major groups or subgroups. The method correctly detected 13 reference DNA samples. A blind test of 237 samples resulted in complete agreement with their phenotypes, and 110 of these 237 samples as well as with PCR-SSP method. The whole analysis could be finished in less than 100 min at substantially low material costs and the template DNA ranging from 0.16 to 500 ng per reaction could be quantitatively detected. Despite the limited informativeness of ABO genotyping, the developed methods could find application in rapid and inexpensive screening of forensic settings. 3 tables, 4 figures, and 26 references (Published abstract)