The onion cultivation in Moldova by seedlings is a relatively new method being implemented by onion growers. The onion seedlings were grown in plastic greenhouse in modular trays with 216 cells. In this investigations there were studied four varieties and two hybrids registered in Moldova. All tested varieties were grown by seedlings. One variety was grown by seedlings and sets to determine the efficiency of seedlings method comparing with conventional method of planting onions by sets. Seedlings and sets were transplanted in open fields in early spring the same day. The results of this study shows that among the open pollinated varieties the highest productivity had Haltedon, which ensure 109 t/ha, comparing with 50 t/ha on Stuttgarter. The most efficient for seedling method are hybrids of onions (Candy F1 – 123 t/ha). Production of onions by seedlings ensures 24-25% increase of yield comparing with conventional method by sets.