Laboratory tests and two field experiments were conducted in 2008 and 2009 at the Research Farm of the Agricultural Research Station, Miyandooab, West Azerbaijan, Iran, to evaluate the effects of hydro-priming, halo-priming (solutions of 1% KNO3) and osmo-priming (solutions of ZnSO4 with 10 mM Zn and KH2PO4 with 50 mM P) on seedling vigor and field emergence of maize. Analysis of variance of laboratory data showed that hydro-priming significantly improved mean germination rate, seed vigor index, shoot, root and seedling dry weights and reduced electrical conductivity of seed leachates, compared with control and other seed treatments. Germination percentage for seeds primed with KNO3, water, ZnSO4 and KH2PO4 were statistically similar, but were higher than those for unprimed seeds. Invigoration of maize seeds by priming with water and KH2PO4 resulted in higher seedling emergence and establishment in the field, compared with control and priming with KNO3 and ZnSO4. Mean Seedling emergence time was also reduced by seed priming, particularly by hydro-priming. Therefore, hydro-priming is a simple, low cost and environmentally friendly technique for improving seed germination and seedling emergence of maize.