To obtain seedless ‘Eureka’ and ‘Villafranca’ lemons in a pollinating environment, we induced mutations by exposing buds (mV1) to60Co gamma irradiation (13.3 Gy/ min; Spiegel-Roy and Vardi, 1989). The irradiated budwoods were then grafted onto Troyer rootstocks. To avoid the formation of chimeras, individual budwoods (six buds from each base) from the irradiated plants were grafted onto fresh rootstocks (mV2two cultivars, we selected one mutant whose yield was similar to that of the wild type. The yields of ‘Villafranca’ and ‘Ayelet’ were the same, 50,000 kgha–1. The yields of ‘Eureka’ and ‘Galya’ were also similar to each other, at 40,000 kgha–1. No seeds were found in either of the two mutant cultivars in contrast to the five to 15 seeds per fruit in both ‘Eureka’ and ‘Villafranca’ (Fig. 1 A–D). The seedless fruits were slightly larger than those containing seeds (Fig. 2). The acidity of ‘Ayelet’ (on ‘Volcameriana’ rootstock) was not significantly different from that of ‘Villafranca’ (on ‘Volcameriana’ rootstock). In contrast, ‘Galya’ was much less acidic than ‘Eureka’ (Fig. 3). The TSS content of the seeded and unseeded varieties were about the same (Fig. 4). Although the sugar/acid ratios of ‘Villafranca’ and ‘Ayelet’ were about the same, the sugar/acid ratio of ‘Galya’ was higher than that of ‘Eureka’ (Fig. 5) as a result of the difference in the acidity of these two cultivars. No horticulture problems were observed on the mutant’s lemons versus the weight.