Analysis of Random Amplified Polymorphic DNA (RAPD) was evaluated as a tool for testing hybrid purity in tomato varieties. Four F, tomato hybrids (L. esculentum Mill.) and their parents were analyzed with eight 10-mer primers. Out of the primers tested, five primers generated useful RAPD markers to determine the hybrid seed purity of three varieties. Also, various combinations of a primer (AF14) were tested by sequence extension of its termini in order to increase the utility of this primer. These combinations presented additional RAPD markers to test hybrid purity of more than one hybrid variety. Primer AF14 gave one useful marker for identifying hybrid purity of one variety. Therefore, the use of a primer sequence extended at its termini can be suggested to test hybrid purity more efficiently.