Germination is one of the most important indicators of seed quality, because if germination is fast, better sowing results, uniform sprouting of plants, vigorous development and greater resistance to negative environmental influences, diseases and pests will be achieved. Today, with the aim of producing the highest quality seed material, various technologies are used, most of which can have negative consequences for human health and the environment. As an alternative solution to increase the physiological quality of the seed, electromagnetic radiation in the form of coherent light can be used. The aim of this study was to determine the effect of coherent (laser) radiation on onion (Allium cepa L.) seed germination. Onion seeds were treated with two lasers of different maximum output power (100 and 200 mW) in two different treatment durations (60 and 120 s). Hybrid (Daytona F1) and varietal (Majski srebrenac) seeds widely used in production were used in the research. An increase in all observed parameters was found in all treatments except for Dayton F1 samples treated with 100 mW laser for 120 s, in which there was a decrease in standard germination.