Row spacing of new alfalfa stands varies by equipment and individual preference. Seeding rates are often reduced as row spacing increases based primarily on the assumption that increased competition within a row will reduce stand density over time. The objective of this experiment was to evaluate yield and persistence of alfalfa seeded at different row spacings but at the same rate of pure live seed (PLS). Two commercially available alfalfa cultivars (‘Hybriforce 400’ and ‘6400HT’) were seeded at two locations (Brookings and South Shore) in eastern South Dakota at 18 lbs PLS/acre in 2005 and 2006 using three row spacings (0, 6, and 12 inches). Plots with 0-in row spacing were seeded with a Brillion-type planter while those with 6- and 12-in row spacings were planted with a Carter plot drill. Stand density (plants/ft²) was determined approximately 30-d after planting and during fall of the seeding year and during spring and fall the year after establishment for plots seeded in 2005. Due to winter injury at Brookings during winter 2005-06, stand counts were completed only in July for the 2005 seeding. Row spacing affected stand density in 8 of 11 instances (P < 0.10) during the year of and year after establishment, but affected yield in only one of five cuttings (P < 0.10) across sites. In general, 0- and 6-in rows had higher plant densities than 12-in rows during the establishment year. However, differences were not always significant and tended to diminish the year after establishment. Averaged across sites, seeding year stand densities 30-d after planting were higher in 2005 (61.7 plants/ft²) than 2006 (43.4 plants/ft²). This was probably related to more timely spring precipitation in 2005. Due to its small seed size, 6400HT generally had higher stand density than Hybriforce 400; however, cultivar did not generally affect yield.