Invasive plants disperse to new areas via numerous pathways. Study of these pathways helps to focus limited budgets toward prevention and early detection. This study examined potentially invasive seed contaminants in imported crops and grass seed as pathways for plant dispersal to Alaska. Crop and grass seed were purchased from 13 Alaska retail outlets representing 14 seed suppliers. Seed bags were sampled using federally mandated protocols and were analyzed for crop seeds that were not supposed to be included and for weed contaminants. Ninety-five weed and 36 contaminant crop taxa were found. Crop seed contained 43 weed taxa and 15 other crop species contaminants, a mean of 6.4 taxa and 3,844 contaminant seed kg−1. Grass seed samples contained 73 weed taxa and 21 crop contaminants, a mean of 3.5 contaminant species and 1,250 seeds kg−1. Two species prohibited by the Alaska seed law were found: Canada thistle was found in a single crop sample, and quackgrass was found in two grass samples. There were no significant relationships between either seed type or supplier and either the number of contaminant species or number of seeds. Labels of 33% of crop samples and 8% of grass samples claimed 0.00% weed seeds, but low (0.007% by weight, 2 species) to high (1.18% by weight, 13 species) amounts of weed contaminants were found. Importation of crop seed is a large pathway for seed movement, causing significant propagule pressure and an increased likelihood of establishment by new invasive plant populations. Prevention of spread via this pathway would be enhanced by changes to seed laws, by greater regulatory enforcement, and by including on the label, the names of all weed and contaminant crop species found in the law-required samples. Consumers could then make decisions on whether to purchase seed based on the potentially invasive species that would be planted with the desired seed.