summary We developed a polymerase chain reaction‐sequence‐specific primer (PCR‐SSP) technique to screen for hybrid molecules in the MNS blood group in the Thai population using two sets of newly designed primers specific for four GYP(B‐A‐B) hybrids, GP.Mur, GP.Hop, GP.Bun and GP.HF, and two GYP(A‐B‐A) hybrids, GP.Vw and GP.Hut. One thousand and forty‐one blood samples were tested with human anti‐Mia by conventional tube technique, and 598 samples of these were tested by the PCR‐SSP technique. Ninety‐four samples (9·03%) were strongly positive with human antisera by conventional tube technique. For PCR‐SSP test results, the GP.Hut, GP.Mur, GP.Hop, GP.Bun and GP.HF genotypes were amplified with the first set of primers, whereas GP.Vw genotype was amplified with a second set of primers. The GYP(A‐B) hybrids (GP.Hil and GP.JL), GYP(A‐B‐A) hybrids (GP.Nob, GP.Joh and GP.Dane), GYPA, GYPB and GYPE were not amplified by either set of primers. Results of testing 94 Mi(a+) and 504 Mi(a−) by conventional tube technique and PCR‐SSP were concordant. This study shows that analysis by PCR‐SSP is simple and convenient; therefore, it can be used as an alternative to conventional tube technique for mass screening for MNS hybrids, especially when specific antisera are not available.