Almond, Prunus dulcis Miller [D.A. Webb], is gametophytically self-incompatible. Therefor establishment of commercial orchards, it is needed to select and grow at least two of its cultivars that are compatible with each other. Determination of self-incompatibility in almond can be accomplished in several ways, the most recent method being by the use of specific primers in PCR. In this work, a pair of primers, AS1II and AmyC5R were employed, to determine incompatibility in some Iranian cultivars and genotypes available in the Horticultural Experimental Center of the University of Tehran along with some foreign cultivars used as control. This primer pair employed to determine s-alleles such as S1, S2, S3, S5, S7, S9, S10, S11, S12 and S13. In this experiment, the foreign cultivars showed the same size of S-allels as stated in the previous reports, so the known foreign alleles were taken as basis of the assessment of Iranian cultivars and genotypes. The Iranian cultivars and genotypes showed alleles as follows: "Yalda" with 1100 and 2000 bp belonging to S1 and S7; "Shahroodi", "Azar" and "Shokoofeh" with a size of 1200 bp belonging to S3 or Sf; "Talkh-13" with 2000 and 1300 bp which belonged to S7 and S12. Genotype number (5) with 1200 and 1400, the first one belonging to S1 and the second one to S13 Genotype number (11) with 1400 bp which belonged to S13.